"Normal" wholesaling terms for buyers?

[Bienes Raices]

As a potential buyer, I've been dealing with a wholesaler in my area and I'm not sure if the conditions they've set for the buyer are typical.

If you don't mind sharing:

1) How much of a deposit do you ask for from the buyer?
2) Is the deposit refundable or non-refundable?
3) Is there any kind of inspection period for the buyer?

Thanks.