I second ebay as a potential venue for selling. Keep in mind that almost anything (house, car, RV, etc.) will sell if priced at market. When selling anything, what you paid for it or what you owe on it is totally irrelevent to the buyers and is not a valid factor in pricing. Folks who bought homes in California or Florida at the height of the bubble can attest to that. The current market value of such homes may 1/2 or less than what someone paid or owes. If you want to sell your RV, price it to market, not based on your personal situation.
That said, ebay brings you a large group of buyers and sellers and provides, at a minimum, information about the market price. In your local community, there may only be a handful of people looking to buy a Class A RV at any given time. Too few buyers. But expand that market to the entire US and you have literally thousands of interested buyers. Just as you would be expecting some type of discount for long distance buying solely on the basis of the seller's reputation, his description and some pictures, you should not be surprised that bidders will expect to get some reduced price because of the perceived risk. If you buy anything on the internet, you expect it to be priced lower than a local retailer because of the potential problems after delivery, delay in receiving it and returning it, etc.
I have been tracking a lot of Alpine auctions on ebay in recent months because a friend is looking for one. Here is my tally of actual sales of Alpines on ebay:
2002 36FDDS sold for $50,001 on Aug 29
2003 36MDTS sold for $57,900 on Jul 28
2003 40FDTS sold for $72,101 on Aug 14
2005 40FDTS sold for $79,300 on Aug 29
I also see a lot of unsold Alpines with high starting bids that no one bids on. For example, one seller has repeatedly listed a 2001 40FDS for a minimum bid of $74,900, which IMHO is too high for a 2001 single slide in this market. See above comparisons. Maybe someone with too much money will come along and buy that rig but I doubt it at that price.
From what I am seeing, your 1999 should sell between $35,000 and $40,000, depending on condition, maintenance, age of tires, etc.
Jaime & Dave (and our 3 cocker spaniels)
2005 Alpine Coach 36FDTS w/ 2009 Honda CR-V, Doran TPMS, Roadmaster Towbar, US Gear Braking