Depends on the size of your miniatures, and the detail you expect. If you’re looking at the typical RPG miniatures in the 25-30 mm range with fine detail, then you’re looking at the liquid resin printers. Nasty to work (chemical handling and fume management) with and more expensive than the fused filament type. Results can be as good as you’ll see on Warhammer injection moulded miniatures.
If fine detail is not of concern, or you’re going after larger miniatures (90 mm +), then the fused filament is the way to go. You can replace the standard 0.4mm print nozzle with a smaller 0.3 or 0.25 mm nozzle to give better resolution, but print at slower speeds. For example, if the low detail quality you see on the average resin cast minis you get at the hobby store are good enough, then this choice should be fine. An Original Prusa Mini+ will fit your budget.