I'll still offer $150 for the alpine. cause they are brand new not refurb on ebay for $175. electronics are like cars. if you drive it off the lot you'll loose 20% of the value off of it. but your choice.
heres an idea for ya to replace a heater core. Sell your car. It takes alot of work to replace one. And look about spending several days replacing it if you are mechanically inclined.