If the shank isn't cracked, the stem can be replaced and I don't think it would cost more than the pipe is worth. I've seen old meerschaum pipes in antique junk shops selling for $150 or more and some of those were obviously not repairable.
Now, cleaning the outside of the pipe is another question. I've heard that some people do manage to remove surface dirt and grime from meerschaum but I don't know how to do it.
As others have said, there is probably not much resale value in it but then again, value is relative to the person buying the pipe. Some might value it around $25 but others might buy it in the $75 to $100 range. Then there also may be a collector out there buys horse related items and would pay even more.
Personally, I would value it more as a family heirloom/keepsake and just clean it as much as possible, remove the tape and see if the stem is repairable (it may just be a screw in tenon in the stem has broken). I would put it in a display case after smoking it at least once. It could be something to pass down to future generations.