Rough costs to build a garage?

[rash_decision]

Hi, I'm wondering if anyone is able to give me a rough cost for building a garage? I am able to build it myself, but having always been able to "aquire" timber for previous projects, I'm unsure how much material will cost!

I currently have enough 22mm ply for the roof, and ample felt to cover it, so only need a rough idea on cost for the framing and shiplap for cladding. The garage will be roughly 6m by 3.5m.

I'm just trying to weigh up costs against getting a company in to build one for me.

Cheers!

[rash_decision]

Sorry guys, some more info! I have a concrete sectional garage that has seen better days, on a good, substantial base. Basically all I am looking to do is dismantle the sectional garage with rotten roof, and build a nice new timber garage on the existing base. I have material for the roof, a new up and over front door, a UPVC side door and a double glazed window for it.

The garage will be roughly 2.2m wall height.

I don't know where the best place to get timber from? I'm in the Glasgow area, and find vast differences when looking online for prices. I'm offshore at the moment so can't visit any timber merchants to price up 3x2 or shiplap.