On the up-and-up

Before paying any money, make sure the organization is on the up-and-up.

You double-cross me, you son of a bitch. I bet English gave you a sawbuck so he could take her out and give her a jump, and you sit back there collecting fifty bucks from me becuss^([sic]) I'm sap enough to think you're on the up-and-up with me.

“Which you also have to order from his Web site, I'm betting. Are you sure this doctor is on the up-and-up?” “He wrote a book, Abs. Of course he's on the up-and-up.”