you cant keep cooling air with out and ac in a basement. all the exhaust from the hoods and room will raise the ambient temp of your basement by 10*+ easily. then if its summer and hot as shit out, well you might wanna forget about running your room. even with my ac, inn summer my temps go up 5* than in fall/winter.
and don't exhaust anything out your h2o tank/furnace exhaust stack. it can back draft, potentially blow out the pilots, and create a very dangerous/deadly carbon monoxide situation and kill everyone.
my 14k was 499, plus 100 for a 5yr ext warranty
I also have a 8k btu LG unit as well I was using before I upgraded my room and added another 600. iirc was 298 + 80 for a 5yr ext warranty.
if your local Ill sell ya the 8k for a decent price. my current unit is 6 months old, and been used for 2months, and still 3 yrs on the warranty.