[skippy05]

Your expectation of price is off by quite a bit. This will at a minimum run you 23k +. Now for some advice that no one else on here will give you but it is very important: If you want to have a mini-split AC in this room, one of those exterior walls MUST have a header area of wall ABOVE the window that is at least 16" and 20" header above that window would be even better. Yes, there are ways to have a mini-split that do not require what I say, but those will cost you, even more, to do (2x the cost). Therefore BEGIN your plan with which wall you will create with a window that has at least that much wall (header) above the window (as from the inside the room perspective) up to the ceiling. And, take one guess as to 'why' I know this to be true? (I didn't know or do this and my mini split had to be one of those which HANG from the ceiling because I didn't plan and that cost me 2x on my mini split. Oh, people will tell you don't worry you can get one to squeeze in the small space above the window and you can just have an inline water pump to deal with the condensate water instead of gravity pipe. Well, only do that if you ENJOY listening to an inline condensate pump vibrate loud every 20 minutes on a cycle! Thus I was forced to do a ceiling hanging version that cost 2x the cost but then allowed me to do a gravity drain pipe out the exterior wall.