Consider that concrete is $105-115 per yard you have about $2300 in material alone just for the slab and that does not account for the labor and materials to prep for the pour!
T-111 siding is going to be around $35 per sheet and that is 9' sheets... you can do the math on that. A decent roll-up garage door with a good belt drive system will be $12-1500 MINIMUM.
I haven't ,mentioned framing materials or electrical considerations....a 200' roll of 12-3 copper is about $90 last time I checked, how many rolls will it take to wire what you want, and what about light fixtures????
Seems to me that if you got this done by a professional for around $20k you would be getting a good deal.A $9000 swing is too much. Either one of them is gouging or the other is lowballing to get the job and will "change order" you to death. Ask for itemized specifications of everything that is included and not included, you don't really need each line item price but you do need to know what you are getting!
Oh yeah, do you want to insulate it and sheetrock the walls also???
These are California figures and we have outrageous building permit issues that add to the cost as well.
Just do one thing ...PLEASE... whoever you are considering for the job, get MANY references and call ALL of them. Anyone can give you three names of people who will say nice things about them. If a guy has been around a while and has his stuff together, he should be able to produce a good sized reference list in short order.
You get what you pay for in the construction industry...unless you are buying a new production home ,in which case, you are getting f@#$%d!
Good Luck
Darius
A remodeling contractor in No. California with 26 years in business.