If a fellow pro didn't introduce you to them, then I would say pass, unless your last name is Walters or Brodendorfer..just how many outs/limits do you need to fill up on certain games?
Besides, unless you're independently wealthy, why would you risk the untimely stiff when a fat payday comes after a batch of small to moderate square-ups?
There are many credit shops across the US and abroad that are Dun & Bradstreet worthy(deep pockets), but if you're not introduced by proper channels, then why gamble?
In the day and age of generic numbers, and tighter lines, the 3 second phone race for best numbers are over, just pick the winners at reliable outs, and don't worry about having to win your money twice.
Just say no!