I bought it finally. $800.
Price not bad for a UW(2009) L lens. (compared to similar item online)
I tested it thoroughly from f2.8 to f22, 24mm to 70mm. Also shoot into bright light too. Doesn't seem to have any issue. I will use for a while before sending it for repair after I have saved up enough money.
After repairing, I may be able to sell it for $800 to 900. They cost of repair will be considered the rental for this L lens.
BTW, I do lend and borrow things but if I do any damage to them, I will be responsible. lol