The BEL range for hatchling males nowadays seems to be around $350~$450 at the least, and isn't too uncommon. For a 3 year old male, maybe $500~$600 would have been fair. Females tend to be the ones to go for $550~$700, but even $700 adult females are hard to sell. So this price you found him at is a nice deal, but not incredibly insane. Go for it!
Male BELs going for $800~$1200 might be a few years ago already.
(For the record, the price ranges are just from my random observation from spying on faunaclassified daily for a few months LOL)