Not that I can afford even this small investment, but...
 

My friend has a 1996 Volvo 850 sedan with a failing automatic transmission. He needs it gone in a hurry, he lives in Germany now and is going back next week.

Any guesses how expensive and difficult it would be to put a manual transmission in it? That could potentially make a reasonable car for me.

Edit: That may not have been clear. He lives in Germany but used to live here and is visiting now.

I am planning an auto to manual conversion on a 94 accord next moth. All the parts at a local pull-a-part cost me about $170 a few months ago.

You can see prices here but you will need to choose a location before the prices will show up.

At minimum, you will need the trans, flywheel, pressure plate, clutch disk, floor console, shifter and linkage, clutch pedal and cable or hydraulic lines (slave cylinder will be attached to the trans if it is applicable).

You may need the manual transmission version of the starter and axles- to determine that, simple go to an online parts store, like autozone.com, and select the volvo with auto and manual trans and see if the axles and starter are the same or different part numbers. For aesthetics, you may also want the manual trans version of the dash (no PRND indicator lights) and you may need the manual trans ECM- or trick the computer into thinking the trans is in neutral all the time so the starter will work.

The brake pedal on autos is usually wider than a manual trans car, but rather than getting the manual style, one could simply cut part of the pedal edge off.

It will likely be a 20-30 hour job when you consider how much time it will take to pull the trans and parts yourself in the hot pull a part yard. But hey you get the practice for when you do it on your own vehicle....

I bet the parts cost would be $500+ if the junkyard hands you the parts over the counter.

Looking at volvo forums, it seems to be a very common project for that car, and it seems that that car is a particularly easy car to do the job on -- but also expensive, at least the way most people are doing it. They are mostly using expensive racing parts, though.

I don't care what it looks like, so no dash stuff for me.

There's no Pull-A-Part locations around here but I did a car-part.com search and came up with transmissions locally for $150-200. Other parts:
Flywheel - $25-50
Clutch disc - $20-60 (if I want one from a junkyard at all, which I'd probably give a try)
"Floor shift assembly" (maybe shifter and console?) - $30-50
Slave cylinder (if it doesn't come with the tranny) - $25
Axles (necessary for this car, confirmed) - $20-25
They don't have listings for the other stuff you mentioned.

That's easily $400 right there...nowhere near as bad as on those Volvo forums, even if it ends up being twice that. Those guys are spending $2500 on the DIY job!