When did they go out of business? I know they are pausing operations and selling some old inventory but I don't think they are totally gone yet. PON Holdings which owns GT now after the Dorel sale is unlikely to get rid of a bike brand. While the bicycle side of things is quite small for PON in the grand scheme of their company it is a very very important part of what they do being Dutch. The company is massive and go into some really weird sectors of business.

If you are trying to get highest value get the bike as clean as possible adjust the handlebars and stem to the correct position and follow the rules for taking bicycle photos and take lots of good photos and stick to the drive side. https://theradavist.com/photographing-bicycles-how-to
In the end the effort will probably net you $20-100 but certainly you can always try to ask for more. But a 26 year old bike that was around $400 bike new doesn't hold much value.

This can be a starting gauge for pricing some people don't love it because there area is really good for sellers and you can get more and some are bad and you get less:
https://www.bicyclebluebook.com/valu...condition=GOOD