If you already have an A/C a furnace is very very cheap, so cheap it's almost free (i.e. included with the A/C). I don't see how you can possibly save $37,000

If you already have an A/C a furnace is very very cheap, so cheap it's almost free (i.e. included with the A/C). I don't see how you can possibly save $37,000 just by getting rid of the furnace - they just don't cost that much.