Nothing like a METAL tank, I totally agree....and if volume isn't an issue, I won't bother recommending an Acerbis tank which is way nicer and of better quality than any of the others.
That said, I put a WTB ad on CL for a DRZ S tank and believe it or not got more than 1 response. I bought a yellow one that had a minor scratch (surface only) and took it to the local powder painter. He sandblasted it down to metal and powder painted it black, which is what I wanted. You could obviously paint yellow. I only paid $35 for it and with everything said and done, it came to less than $100 ($87 and a 6 pack). Try it, you may get a taker..............just sayin'