I would not do this. It is not failsafe. Is your credit union willing to give you a written guarantee that they will make payment good if funds fall through? No? Then doing this "all the time" means nothing.
Don't do it.
This. I used to work at a CU. The scam works like this:
Make lots of car deals.
Get a real cashier's check for an amount that will buy easily saleable "hot" cars.
Print 20 copies of said check.
Close 21 cars. Bank gladly verifies that check #4722 is good and amount stated is valid.
{weeks pass, 21 cars are sold}
First check clears, 20 fakes bounce.
Criminal profits 10-15x investment.
Go with him to his bank. Have him write a counter check (or cash whatever check he has) and give you cash. Deposit in bank if you have an account, or have the bank transfer your cash deposit into your bank or write you a cashier's check.
I do this with any CL type sales over a couple hundred bucks. Added bonus, banks have all kinds of cameras and stuff in them.
It's safer for the buyer too as they don't have to carry cash and take the risk of you theoretically robbing them.
This.
