Well I'd try and patch the leak if you can find it before finding a new tank but that's just me. And not really having a good sense in how or where it's leaking is preventing me from understanding the exact problem and the best course of action to take. If you can post a pic of the leak that would help. But I'd try patching it via epoxy or some glue and patch combo. Try your local autoparts store and ask someone about fixing a leak in a gas tank they should have something. Wether it's a long term fix or a short term it should save you cash until can locate a new tank or just sell the bike.
they should have something tho I mean they have headgasket fix and piston ring fix in a bottle and thats all mechanical based problems.
