vw bora tdi pd key trubbles

Hello all iv got a bit of trouble ,I need a key for my vw bora where can
I get one without being ripped off. vw wanted 250 for the key,I
dropped my key down the drain out side my house,I tried to dry it out
but its no good.i still have the key blade can i buy a second hand key
off ebay switch the key blades and chip and get it coded ?I did try to
replace the casing but vw said they tried to code it but they couldn't sort it any help please?????