I had Coyote make me a couple of tanks, they are here in AZ so not bad shipping and if you look at their site they will custom build you a tank for about the same price as their stock offerings.
I think I paid about $115 for this custom one delivered.
That one had tabs welded on so I could use a couple of the 3 hole rag joint sprocket mounting pieces to attach it to the seat bolts and an extra long offset filler hole.
This one may have been a stock size I painted to match the bike but both are over 1/2 a gallon.
A V8 or green bean can (have one on my desk right now) are just to small for most peoples needs unless you want to constantly keep an eye on fuel.
$250 for a tank is excessive in any book unless that book is 'How to gouge enough to buy your own Island in a year' or the like ;-}