Some of it will come down to your priorities, but I can give you some tips. My biggest concern is always making sure the unit has a good reputation repair-wise. I got stuck with a lemon of an AC unit a couple of years back — it broke five times in the same year one time. After that, I always check to make sure a unit is hard to break and easy to repair before putting down any money. A good AC repair services Denver CO company like JDs Plumbing, Heating, and Air Conditioning can keep a troublesome AC unit running for you, but the service charges will add up over the years.
If you also want to avoid that sort of trouble, you should stick to air conditioners that have been in the market for a year or two. Those will have gathered enough long-term reviews to give you a sense of their reliability. Or better yet, call your local friendly HVAC company, and ask them what models they recommend at your price range. You can also figure out how much it’ll cost to get that model installed in the same call.