Everything I've read suggests that Amanos are THE algae eating shrimp. Although I don't think they'll breed in FW. So you might go with Cherries, who also gobble up algae like no tomorrow and happen to be quite prolific little breeders... I think I've got three or four pregnant ones in my tank right now... as for cheap I would suggest looking on ebay or Aquabid. I got mine on ebay and with shipping it worked out to be about $2 per shrimp, which is half of what my LFS sells them for.