On the topic of prices and what you should expect, it is ultimately up to you and what you want from your goods.
However remember to take into account that there are people on eBay and here that can feed my addiction at 25-30% off retail. If you want your New in Box stuff to sell, remember that you are competing with the stores. Expecting 10% off retail isn't going to get your items sold when I can just go a few threads over or a quick eBay search later and get them for 25% off. Unusual items or hard to come by items will sell for more since they are hard to come by. Usually when I sell NIB stuff I like to take 20-25% off retail, this puts me at par with the other people out there selling items and most of the time people barter any ways.
Remember this is a US based site and so your prices should be in USD. Most of the users will look at the price and automatically think USD unless specifically addressed (and even then most people tend to not read the whole post). Don't expect getting your Canadian value in the models, not when in the US they are cheaper. If you stick to USD prices they will sell better.
Painted models can go either way, if they are expertly painted they can go for a higher of a price if they are a full(er) army. Unless the paint scheme matching an already existing army (like ultramarines), it's going to be hard to fit painted models into a scheme unless there is enough points to be an allied attachment or stand on its own. Not many people like paying a higher price for a squad that is going to stand out from their already painted army (unless it's on purpose).
Badly painted models or "Tabletop" models are not going to sell as well as you may hope. Remember, if I can get my models new in box at 25-30% off retail, I am not willing to pay equal to that or more for a model I am going to have to strip and clean. No matter how well you think you can paint, there will always be people who are A) better than you and so your quality is not up to par or B) wanting to strip the models because your colour scheme doesn't match. Usually when I sell painted models I put them up for 50% off retail.
Do not put "Pro-painted", "Expertly painted", "OMGZ the coolest, pro-painted army in the UNIVERSE!!!!!1111!!" unless it truly is painted that way. Too many people put this in their title and thread as well as on eBay and the paint job literally sucks. If your going to sell your army "pro-painted" it better be painted by a pro, and not the "pro" at your local hobby store that paints better than the rest of you but only at a tabletop level... A pro that does this for a living. Go look at SpiralingCadaver or GardenNinja... those are pro-painters. If your model is not at least up to that quality, then it's obviously not "pro". Most people expect pictures of pro-painted armies in your thread, remember from my last post.. If it's pro-painted, please show us that it is with nice clear pictures. Your selling not only the models but the paint job as well. I should go into a "pro-painted" thread expecting to have my mind blown.
Out of Print (or OOP) models don't hold the same value of newer edition models. The only exception is limited OOP models or people specifically looking for them. The best way to look at OOP models is to slap an extra 10% off, this helps sell your models. Many people don't want older models and having a nice price to equalize the fact that it's OOP can help. Usually I sell OOP painted models for 60% off retail. OOP new in box models go for 30-40% off. When you create your post and prices, design it towards people looking for the newest models, this will usually help deciding on what price you want for them.
Anything else is really up to your own judgement, if you only want to sell your army as a whole, please ask for a price that will make up for A) the quality, B) any older models and C) the fact that many people don't want your entire army or specific models. When the thread asks to sell the army as a whole you have to realize that I might only want 50-75% of it, why do I want to pay you for the full army when, again, there are other options out there. Adjusting your asking price on large armies will help sell it better.
Remember that the internet is cheap and this is Bartertown. Bartertown comes with bartering.. it's in the name. Do not get upset or insulted if someone offers you a lower price for your army. If you did not wish to trade with a community and barter than "Barter"town is not for you. Remembering that people are cheap will also help sell. By cheap I mean, people don't want to put a lot of money into their already expensive hobby, ESPECIALLY if they have to put their own time into it. A full, badly painted army that will require stripping, cleaning, assembly, etc is NOT going to sell for a lot and to expect it to is just silly. Even on eBay your not going to sell your army for very much, maybe 50% of retail. Then, eBay fees, Paypal fees and everything else comes out of it. Don't automatically think "oh well I can sell it for 200% on eBay".. good luck, unless it's pro-painted (and I mean actually pro-painted) I personally am not going to bid higher than 50% for an army unless it's ALL new in box/on sprue.
Overall, it's your decision what you want to sell your models at and no one can tell you anything otherwise. Just take into account the rules of thumb and you'll do fine.
Rules of thumb:
1) Models can be found new in box at 20-30% off retail on eBay and Bartertown advertisers.
2) Don't label it Pro unless it truly is.
3) Do not expect painted models to sell at the same price as I can get them new in box.
4) OOP models will not sell at the same price as newer edition models unless someone is looking for them specifically.
5) You competing with the internet.. make your value exciting, set it at a price that people will think "Holy crap that's a good price".
6) Remember your models, paint job, assembly time and all those hours of sweat and blood going into your army means crap to everyone else.
As for pictures and how to set them up it's again a very bias opinion. I usually like to include pictures that are linked from Photobucket. Remember that you have a maximum of 5 pictures per post if you use Bartertown to post them (the built in picture upload feature). Using the reply option to upload more posts of purely pictures with no obvious edit of the original post is technically bumping your post and will get it locked. By linking the pictures from a picture hosting site (in the advance/full editing text box there is an option to link the url of your pictures) you can fit more into your thread (like hundreds and hundreds). Try putting pictures at the end of your post to help keep things clean, the more pictures the better obviously. Some people just put the link to their online album and that is also fine, the pictures don't HAVE to be in your thread, but having pictures will greatly increase your chance of a sale/trade.
Hopefully my, once again, bias opinions help
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