Where are you located, Stevie, if you don't mind me asking?
Have you looked at any online vendors? I would try
MegaHobby, for one, which is the online vendor for Stevens International.
Another online vendor to check out is
Sprue Brothers.
And there's
Squadron, too.
Other forum members will no doubt have good suggestions, too.
As far as using the craft store paints goes, I use some, too: Apple Barrel, Americana, and Folk Art. As water-based acrylics, they work well with my wet palette, and as Belugawrx says, they can be used to mix colors well, and they are very reasonably priced for the volume. They can be airbrushed, but I found when experimenting airbrushing them, that their pigments are relatively coarse compared to scale modeling paints made specifically for the hobby. It didn't impact spraying them through the airbrush, but I found that the finish was a little rough. But you can mix them and let the coarser pigment settle out first.
Hope that helps, best regard,
Brad