I doubt it costs that much. You’re looking at it from buying PC components perspective. But they are mass producing identical boards with components that are 4+ years old by now, except the GPU. The cost of production is probably around the same as it was for non-Pro when it was released.
To be fair, PS2 emulation is still not that great, but I guess it’s due to sheer amount of games for that system. Last summer I decided to check the PS2 emulation after 10 year break and 2 out of 3 games I tested didn’t work properly. Granted, those are kinda niche games (Transformers (2004) and Free Running), but compatibility still needs work. Hardware requirements are decently low for the games that do work, though.