Price vs value
If this is a small tank, you ought to be able to get it for nearly nothing. A big tank may come with a lot of stuff included, likely high quality stuff.
I bought a 20 gallon with iron stand for $20, no top, no lights, no equipment, bare tank. I bought an Oceanic 55 gallon with pine stand and wet/dry less pump for $50. I bought an Oceanic 105 gallon, nearly new, fully furnished with beautiful oak cabinet, dual Eheim filters, full of big fish, decor, all food, meds, and tools for $500.
Beware of a Walmart special, with thin glass tank, pressboard stand, incandescent lights and no name equipment.
Quality stuff is fine to get used, cheap stuff is likely broken or ready to break.