I dont know... when it comes to high end electronics I try to only buy from sites I trust and look to be legitimate.
Iv bought from HTCpedia.com, amazon, newegg, ect. and Now I would buy from the android central store after being a part of the community. if they all dont sell it i take it as its not a product worth buying.
with that said.. I do not believe those are "real" htc batteries..and you should be wary. as Jerry said some of these after-markets are ok..some not so much.
good luck.