Oico,
There have been several guys that have done this in the living room as well as a shed.
There may be someone nearby willing to help. Where abouts are you?
There is also the possibility of using one of the engine builders/fabricators here in the forum worth contacting.
The numbers you have as far as parts cost look close barring shipping and handling.
Gaskets,seals,bearings,consumables and some special tools are also a factor.
(case splitter, flywheel puller, clutch holder torque wrenches etc)
I am sure you can do this, I have and am by no means an expert. If you can put together a 300 piece jigsaw puzzle you can re-build your engine.
If you aren't cracking open cases more than once a year it's hard to justify buying the tools to be able to do a good job as they are not out of reach, unless you really want to do it yourself.
Hopefully some of the other guys will respond with another point of view..
Tuck\o/