I don't think he was being insulting or undervaluing the bike at all. Honestly, in the condition it sits in those photos, it's probably a good starting point on the price—and even then, they will need to be spec'd with XTR and the rarest of components to warrant a price tag like that. Only the cleanest, freshest examples of Yo Eddy complete bikes will fetch anything even close to $1500. The coveted 10th Anniversary bikes, which were very limited production, are in the range of $1700-2000 on a good day, and that is for pristine examples.
I just picked up a stellar similar-era Wicked this fall in a very rare color combo, for right around $500, and all things considered, it's in much finer condition than your Grello Yo. I don't think he was being sarcastic in the least with that offer.
As someone previously wrote here, clean that frame up a lot, remove the extra decals, take much better photos of it, and you might have a shot at getting more cash out of it should you decide to sell. But in a market like we are seeing right now, only the cleanest bikes are going to get top dollar, and even then...
Good luck with the sale, but you need to be realistic with what you expect to get out of it.
doug