What are you doing wrong? Really? You
really have to ask... OMG
Well, ok. I sold some painted miniatures baaack back then (some 10-15 years ago), so i think i could give you some advices.
When you sell miniatures, its value depends on the status of each miniature. Usually you can get more money when they are closer to the condition you can expect from a store (new in a wrapped box). From that point on, you get less and less money for them. So you get less when they are in sprue (without box), less when they are in pieces... The worse condition is a model assembled and painted. Badly.
You can only expect to sell miniatures for prices above RRP when they are really really WELL painted. And even then it is difficult, very difficult. To sell a painted miniature you cannot put in the title "pro-painted", that is a viewer discretion assertment, and you cannot sell them with "Buy it now" fixed price. You have to have an auction with 1$ as starting price. If your mini is really well painted it will be sold for a fair price if you chose a model with high enough demand. As i said, i sold some models for 40 - 50 € each, but they were extensively converted (one or two fully sculpted models) and carefully painted miniatures. And they needed a lot of work of "advertisement" in many forums, web sites, etc. And list them in ebay several times each one... So, even when the models are truly good and beautiful, it is really difficult.
Now, your minis?
I'm afraid your minis are not good... First of all, your miniatures are shown in very poor photos, but that is a minor inconvenience. Truth is, your miniatures are badly assembled and awfully painted. I can see mould lines, parts badly glued, and then the paint is thick, the colours are very flat and everything looks so dirty and messy. Sorry to be blunt, but it is really awful.
You cannot expect to sell them for more than the RRP, never ever. Almost anybody can paint to that "standard" easily. People looking for painted miniatures look for way better paintjobs and way less price, and people who are looking for miniatures look for the cheapest and easiest option. With that i mean that a lot of people who might buy your minis (in case they would be fairly priced) they would strip the paint, unassemble and clean them themselves, so it is an extra work needed for that models... It would be much more easy to buy the sprues, as well as much much more cheap. There is nothing to appeal somebody to buy your minis. Really.
So, if you really want to sell them, make them all auctions with 1$ as starting price. Then you will see that people only will buy them if they can get them really cheap. As i said, those models require extra work.
Alternately, if you really want to sell them by those prices, you will need to strip the paint, unassemble the models, clean the mould lines and assemble them properly, then prime them properly and then paint them properly. And then make good photos and display them with a nice background.
If you want to follow this route, first of all ignore the "
GW painting system", it just cannot give good results. To achieve rich and nice results you have to MIX the paints, and you cannot abuse of drybrush or washes or any of those "dirty" techniques. Then you have to apply a proper primer, a spray primer or a primer via airbrush. And then the paint you use has to be properly thinned down and learn how much you have to apply and how much to load the brush... And then you have to learn a bit about theory of colour and how the light works, to know how and what colours apply and where in the model... Learn to paint, basically.
In short: Those models are too expensive and too badly assembled and badly painted to be purchased by anyone. Make them auctions with 1$ as starting price if you want to sell them at all cost. Alternately, learn to paint well before trying to sell painted models.
Greetings.
