Anyone know if it's a safe site?
eBay? It's totally safe! They've been around since 1995.
As for who to buy from on eBay, check out the seller's rating. The seller in question has been an eBay member since 2001, sold 30 items, and has a rating of 90 with 100% feedback. Not too shabby!
The drones are listed as "Open box", which means:
"An item in excellent, new condition with no wear. The item may be missing the original packaging or protective wrapping, or may be in the original packaging but not sealed. The item includes original accessories. The item may be a factory second. See the seller's listing for full details and description."
Also of note, these drones are being sold through an auction, meaning they are unlikely to go for the low prices currently listed on eBay.
There are no details about the drones in the listing itself. If you have any specific questions, you should contact the seller on eBay before placing a bid.