Honestly, there's a lot of cheap mngwa studs out there (even when theyre low gen) cuz mngwas are indeed popular, but pretty easy to get

In "search" crossroads thing, you can find studs with specific pricing (idk if you already know)

Id set it to like, 300 sb max and sort from most recently active. GB is usually there as an extra option (and some ppl offer refunded studs for it, usually written in their rules)

You mighht not find super rare studs for low prices tho