Best place to buy large cheap tanks?

[jetajockey]

Is an average price for a used 1$ a gallon ?maybe 2$?

I usually pay about .50/gal or less. Larger tanks (100g+ are worth more though because they are less common).

Cheap Tank Buying Guide - Aquarium Advice

 

[Hobgob]

Yes .50- 1$ I would go 2$ if it has a lid and filter and stuff. Also like mention above a bigger tank brings a higher price as they are less common and normally all set up.
That being sad I got a 110g with oak stand for 150$ I just needed to attach a light to the canopy and clean it.

 

[Tetra1990]

Be sure to inspect the tank before you buy it. If you want a project tank, you want to reseal it, than go for it. Check for cracks on the bottom and corners. some people just want to get rid of these, a bit of wheeling and dealing never hurts. Also, if you can pick it up yourself, the price may drop even lower.

 

[Hobgob]

+1 on the inspection! Unless you want a project maybe even have him fill it before you go to look at it. Then drain it and inspect. If its just the seals that need done it isn't to hard to redo.