Spare engine dilemma

So I emailed my mentors the following question:

I am seriously considering rebuilding my spare TV175 engine now as I
will be building the one to go in my bike. I figure they are both
apart. Bead blast all the cases at the same time. Clean all the
parts, etc. will be easy.

I am also thinking about selling the second engine after rebuild to
help fund my restoration (but secretively I dream about finding
another TV minus the engine and having two). Here's my dilemma the
second engine is missing:

1) Entire kick start quadrant and kick start.

2) Entire top-end and piston

3) Clutch plates, springs, and the top of that assembly.

4) Possibly a crank. I have a good spare, I believe, but the one in
my other engine is currently frozen with flywheel. I just ordered a
flywheel remover tool from Gene today.

5) Bearing, seals, grommets, various hardware, etc.

6) Rear hub

7) Plate that connects to the engine case and then the flywheel

So the question is how much would a stock rebuilt with quality TV175
S3 engine go for. I am fearful that it would cost a lot to build for
a price that isn't much more than I invested in it. My other option
is to just sell the cases and parts separately if I decide to sell.

You guys all build either sell or have sold scoots and possibly
engines too . . . so I figure you guys would be the best to ask.

I have an opportunity to buy FAG or SKF bearings (I think I prefer the
FAGs as it seems they have a slightly better reputation than SKF and
no India factory bearings) for 1/2 the price I paid for NSKs and that
made me start thinking about all of this. If I am patient and rebuild
the second engine slowly I can find good deals piece by piece and
complete the engine at a lower cost, but with high quality.

At this point I am just going to hold on to what I have and see if another TV lands in my lap.

Answers:

"Yeah that's a tough call. It's one thing to build up a motor if you have a lot of spares laying around but quite a diffrent story to have to buy all the missing parts. Also it's a TV175 which can be harder to source all the correct resto parts for (top end espically).

If you still want to build another bike it dosen't hurt to have the case just sitting there untill you find a frame and all the parts to make it a complete bike. If you are worried about cost I'd sell off what you have and find a complete bike to rebuild." - Mike