Help me buy a new Air Conditioner!!1?

It’s starting to get hot and we have just moved, leaving our old busted air conditioner behind, we need a new one and soon! I need help figuring out the lingo.

The last AC we had was 8000 or 10000 BTU, I think so anyways, and it did an ok job of cooling the old apartment. The new place is bigger so I was thinking of getting a 12000 or 14000 BTU, I think that should be fine. Ideally, the way our place is set up, we’d be best off with a small AC in the bedroom and a medium one in the living room but I assume that would skyrocket our electric bill (would love some input on this), so I’ve decided for just getting the bigboy and hoping it at least keeps the living room comfortable.

We now come to the fun (???) part, the only part I understand of all the info is BTU which is basically the power yes? I need someone to explain everything else.

A couple of things I want to know:

How much power does a 12000 or 14000 BTU AC have?

What should I expect to pay for a decent one in that range?

Do most of them use regular plugs? I know that some AC’s require special outlets

Would one big AC be more cost effective then two smaller ones?

Is there a way to tell exactly how much it will cost per hour to run?

Are the energy star ratings worth going after or is it just going to provide a weaker product?

I think thats all (as if it weren’t enough), any other relevant info would be awesome.

Also, I saw an AC at Costco last week that was 12000 BTU I believe for a little over $200, is that as amazing as it sounds or too good to be true?