Bri223,
At that price, if it is a private seller that just joined, only has a few handfuls of posts and is looking to get money sent via PayPal Family and Friends, I'd be very cautious!
However, if seller is a long time Hide member with long history of postings you may have just stumbled into a great deal. I'd first check their posts and search the PX Feedback Section on the Snipers Hide Post Exchange forum to see what their screen name brings up. There are some people here on the Hide that are always chasing that elusive unicorn scope and do turn over a lot of scopes at very decent prices.
Make sure scope is truly "New" and not "Like New!" In my opinion, if it has ever been mounted, it is not new!
On the other hand, if it is a verifiable dealer/reputable vendor, I'd break their arm on it... but would still be left wondering, "why so cheap."
Best of luck to you.
Let us know how the adventure turns out for you!
Edited to Add: Check out "
PX Scammers M. O." posting/warning appearing elsewhere on the Hide.