I found a 55 gallon for sale, how much SHOULD it cost, it's in perfect condition and has a stand with cabinets in it. it has an undergravel filter and 3 hanging filters.
how much should it cost me?

alot

do you know what type of filter they are??

a biowheel 100, 200 and 300
money's not a problem at all, i was jsut curious as to how much it would be... i don't care if it's expensive.

One of our local fish shops has new 55 gallon tanks - the standard All-Glass brand long configured tank - for $72.

I have found that PetSmart, with the price matching that a store will do with their website, you can get the Penquin 100, 200 and 350 filters the cheapest. They are, respectively, $17., $21., and $27.

If your filters are not the AQ PEnguin series, you should still find that they are somewhere in that general price range......

And undergravel filter is not useful for a goldfish tank in my opinion. It is not worth anything.

The cabinet is a big question mark. If it is custom, solid wood it can be worth several hundred. If it is a composite, it is worth considerably less.

Does that help some?

Is the tank set up brand new or used? If it's used you just have to use your eyes & good common sense. If it's new you can search the BIG on-line places to kind of get an idea & go from there.

I got my big tank used & my son went to pick it up for me so he was my eyes. I told him to check the glass and stand for any damage. I really wasn't worried about the equipment. It came with an UG filter which I trashed. Once he called me and verified the glass & stand were in good shape I approved the deal & he brought it home! I have improved ALL the equipment. But the basic tank & stand are great!