Assuming the Exterior is completely dried in, the next steps to finish the project would be:Drywall or Wall Finish - a Cabin in Montana might prefer a Wood Finish instead of the Drywall we typically use in Arizona - Possibly a combination of both; I suspect Drywall would be least expensive but maybe not as Aesthetically correct.Assume an inspection is required to confirm proper Nailing of Wallboard prior to next steps - Make sure Wiring and Plumbing passed inspection prior to installing Wallboard.Tape, Texture, and Paint - If Drywall is used, not required for a Wood Wall Finish, but Wood might need to be Stained and Sealed.Flooring - Carpet, Tile, WoodMillwork - Cabinets and CountertopsElectrical Trim - Includes installation of Electrical Outlets, Switches, and Light Fixtures. 

It looks like that water may be from someone failing to dry their hands after washing them

It also takes days to install with dry times at each step.

Left about 100 workers high and dry.   

They clogged the toilet and failed to ensure it was shut off before leaving town.This may be a big expense because sewer water can't just be sucked up and dried out. you're fortunate it was caught early. 

There are lots of different ACs that you could add, but I would only do so after structural issues are addressed.Plus, from the sound of it, you're going to face some unknown hurdles, so keep your powder dry.

Dry rot and mold would balloon your budget. 

I say that because I can verify employment (neither are self employed 'hair dressers' like a few applicants claimed), they're willing to have a cosigner, and they claim to have savings for when the pregnant one has her kid.

My concrete guy for example instead of pouring the new parking pad and sidewalk in November in relatively good weather, waited until January and then we got lucky with a “warm” 40 degree string of dry days he could pour.

wells are priced of course by a few things.diameter of the bore.depth of the hole..what type of material they are going throughand how much casing. so just check around and get price for diameter and depth then check well logs if they are public for surrounding properties to see how deep the water table is.keep in mind you can have a dry hole move over 200 feet and hit a geyser.My daddy always used a douser local tribe members are some of the best dousers.