for 6-8" thats not bad at an lfs and a 250 is still to small for a fullgrown one...
That is an OK price. It all really depends on the area you come from. Here in MI, one that size would cost about $20. It also comes down to how much you are willing to pay for one.
i think you better upgrade from that 20 before you get a arow and even a 150 wouldnt last long at allThat's how much I would pay.
Is this a good price???
a 55gal would not last anywhere near a year or two especially if he got it when it was 6"-8"ya... thats a decent price and your tank will be good for about a year or two after thet you should go to at least 180 and larger... unless you sell him for about $200 then get a new one and grow it out lol