@Voices is right. @michaelm if you're looking to do a deal onsite here for an item that's less then $100 then people might accept PayPal from you, but anything around $700 and you'll need it to be in BTC, as nobody will trust a new member with that high of a transaction.
Good luck finding an Instagram that you like man.
Also if you're doing a deal for around $700, I'd recommend that you use a middleman in the deal, so you don't have to risk getting scammed.
The best middlemen that I'd recommend are @SoLic and @Zeus