Well, the first and obvious question is what condition is it in? Like new? Heavily used? Is the set complete? Do you have boxes for it? Lots of these factors apply.
That set had an MSRP of $350 (but was likely purchased for less) when it was issued by Lionel over 15 years ago. It's not a high end set.
You mentioned eBay. Not a bad place to start. See if you can find any completed sales for this set and it'll give you a general idea on the market.
