Condition does not look that bad, it's amazing what some metal polish and scotch bright will clean up. If they are proper Termig's and not some other brand with Termig stickers I'd say go for it. Price looks OK to me. May be see if he will do a deal between the auction price of £250 and Buy it now £450 to finish the auction early .... what's the worst he can say, NO
See if he will go for £350 ... as long as the cans are in good condition they will always be worth £350. If you get them for any less your