Lowrance has been giving a rebate coupon for a couple years now on the older Airmap units.
The amount varies depending on what new Lowrance unit you buy.
I bought a 2000C last September with a $275 rebate coupon I received for sending my old Airmap back to them. I bought the new unit from PilotMall.com who happened to have it on sale for something like $699 at the time so my final price was under $450 for a color moving map with terrain software.
Call Lowrance Customer Service and they'll give you the details.
Go to
www.lowrance.com and look for support or customer service to get the numbers. You need an RA from them to return your old Lowrance Airmap.