I already thought out these factors. I do not accept PayPal from new members. For example, I would accept PayPal up to a certain limit from Full members and up, and any lower ranks would only be able to sell their BTC. And what if the price suddenly blew up? As I said I negotiate and update you with questions and concerns regarding it. I would be making enough transactions a day to make up for even one good-sized chargeback. Think of it, if I take 10% of each transaction and deal over $1000 back and forth, that's $100. Now what if it is 20-25%? Even for buying coins I can say Bitstamp + 10% and earn. Being the exchanger you always have the advantage.
Someone is going to buy 10 accounts 10 stolen paypals and clean you out. Sorry to say but it will happen its bitcoin :/
I've ran one before, I only deal with verified users. And I know my limits, if someone sounds sketchy or wants to buy $500+ I know it's hacked.
What happened before why are you still not running it? Please do tell that is very important info.
It's been at least 8 months since I have. And it was only selling the coins. The risk of getting chargedback on is extremely low if you only deal with trusted members. Like opening service for just Senior+ members. This is the only forum that I've been on that is extremely lenient with the buying/selling of accounts, on other forums it'd be much, much harder.