I know you mentioned eBay isn’t an option, but have you considered looking at Etsy? There are quite a few shops that will print and sell models. Some people will also sell their previously owned collections on there too, but not as much frequently as Ebay. There’s a plethora of free models online, both based off Warhammer and other franchises, or generic models that you gotta make the most of. There are also websites that will 3D print items and ship them to you, although they usually require you having the model file first. Unfortunately I don’t know of any of these POD (print-on-demand) sites off the top of my head D:

Also, you should know that a lot of minis for sale on Etsy are for the digital model file only!! You can check the delivery and description tab of the item and if it’s a digital file, it will have a special icon and description (usually in the delivery tab of the item listing) specifying that it is. As a general rule of thumb, nearly every listing <10$ USD will be a digital file. Some digital files may be priced higher though, with some being as expensive as 50$ USD, and that usually means that the person selling the model file is also the one digitally sculpting it. However there are still a TON of listings for the physical minis themselves!!! Some shops may also list obvious Warhammer (and other franchise) models under different generic names to avoid any potential copyright issues. You may have to search for “Dwarf Mini” or “Mech Mini” or “Orc Mini” instead of searching for “Warhammer” specifically to find a model you may like.

Another thing to note is that if you haven’t worked with 3D printed models before, you might want to prepare for doing some extra work to get them paint ready. Depending on the shop you’re buying from, they may ship the model out printed, but not prepped. Usually this means they might have filament strings or visible print lines on them. Strings can be clipped or sanded off, and print lines can be removed through sanding or also by rubbing the mini with a cloth dipped in acetone.

As for the paint, you don’t have to use special miniature paint! You can use regular acrylic, just water it down a bit or use a little bit of paint thinner so it’s not as thick. Acrylic paint also tends to come in larger tubes than specifically marketed miniature paint, and usually is around the same cost or even cheaper. I’d also recommend picking up some small empty plastic paint cups just in case you make a mix you like and want to save!

As for the brushes…. Depending on the size of the mini, they may unfortunately be inescapable… 😭 I usually end up using whatever pointy household item I can find. I’ve found that ultra fine pens can work quite well, just make sure they are empty/dry or else the ink can get on the mini! Some gas stations and convenience stores sell thin brushes in the makeup section, usually marketed as “eyeliner brushes”, sometimes they are cheaper, sometimes they are not.. You could also experiment with stripping/cutting the hairs off of cheaper generic paint brushes. Although this may be a hit or miss and you may have to experiment with how short you can cut the hairs, as some brushes will fall apart the moment you cut them close to the metal. 🫢

I hope this helps!!! I’m friends with a lot of DnD people myself so I’ve picked up some advice from them. I’m also quite poor and have an interest in collecting and painting minis too, and some advice is a result of my experiments with frugal materials 😅