I can only echo what Russ has already said.
I don't know where to buy action figures in the Us, but these two shops are among the biggest in Europe.
https://www.modellersloft.co.uk/ https://www.actionfiguren-shop.com/ As to traffic on this forum, the amount of views, on almost any topic, is quite high, and stand in stark contrast to the lack of actual posts.
I haven't bought any figures in 3-4 years. As Russ mentions the quality/details of figures, from DID, in particular, is mind blowing, but prices has gone up as well. In my neck, of the woods a high end figure can easily cost +200$
Let's us know, if you acquire any figures.