A few years ago you would have been able to buy NOS (NewOldStock) A1200s at several dealer and even NOS A500s from an a.org user (Redrumloa).
There also were some Amiga-clones made quite recently (all sold out), but these were just bog-standard PPC-board in standard PC-formfactor running semi-compatible (no HW-banging) reimplementations of the Amiga-OS. But better not go there.
Today you can only rely on eBay, UAE or AmigaForever (UAE with licenced AmigaOS).