I've been very happy with my intro level Gary Fisher steel mtn bike which I bought used from CL for about $150 4 years ago. It was already pretty well broken in and beat up when I got it, with worn wheels, worn brakes, but otherwise fully functional.

I didn't intend to use it on hard rides at first, but it performed excellently in both offroad climbing as well as urban commuting, so it saw a fair amount of use, especially in the past 2 years. I probably ride it as much as my pricey Cervelo road bike!

It is sorely in need of some work and parts, though. The FD rusted so that it wouldn't shift to the small ring. Then the front shifter broke completely (cracked). Metal attachment of the FD to the frame has rusted pretty good. And brakes are toast.

I think I'd need:
- New shifters
- New FD
- New brake pads
- New cables

I know the correct thing to do at this point is to just get a new better bike, but this bike has sentimental value as well as doubles as a good commuter for me (meaning not expensive and blingy) and I have no room to purchase/store a whole bike on top of this one.

I looked on ebay for altus full gruppos, but didn't come up with anything. Any suggestions about what a good low-cost solution would be here to keep the FD/shifters going?

Brakes do not cost that much 10-15 ea. Kool-stops are about the same. Cables might be rejuvenated by squirting some oil and worked, if not as long as the housings are good can be replaced easily for another 20-25. I don't know what kind of shifters you are looking for, but they can be had used on Ebay, or by looking for a donor POS at the thrift store or Craigslist.

Try to free up the FD by soaking it in some PbBlaster, you can use it in your cables too as it is also a lube, not great but better than nothing.

If you have an 8-speed cassette and a Shimano rear derailleur, I suggest to get Alivio SL-M410 Shifter Levers, not Altus.

If your shifter lever for the rear derailleur is still working, the cheapest replacement for the broken front shifter lever would be to get a friction shifter lever. That would cost around $5. Indexed shifter levers are usually sold only in pairs (front and rear).

I wouldn't spend any significant money on a bike you got for $150 on CL that has seen lots of action. Just scour CL and find another inexpensive MTB in better shape and ride it until it's worn out.

Throw your current ride on CL...you never know what someone may want to pay you for it.