Re: Possible to repair cracked tank?
If you absolutely have your heart set on this toilet and tank, you may be able to have the inside of the tank lined with fiberglass. A fiberglass repair kit at Evil Orange is inexpensive and would have all the materials you needed to do the job, though it may take several kits to fully line the tank, which I would recommend over a spot repair because you would fully line the tank, creating a new, water tight tank. The added benefit of lining the entire tank is that it will help reinforce the entire tank so that the crack won't likely continue.
Second option would be to see if you can find an auto body shop that would be willing to line the tank for you.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!