It is legit^^
However if you wanted the website I use personally I use
Whilst they are getting shameful free advertising from me, it's just that their delivery time for most card types is instant (most certainly UGC). In other words, selling to AP card buyers becomes less of a hassle. Purchase record as kept for eons, and their customer support is fast.
As always stick to the high leveled AP buyers (80-90) because they have much more to lose if they were to scam.