I wouldn't do it regularly but it sounds like you have some plot associated with it.
I guess the main thing for me as a (RB)DM is that big gems attract attention as they are easily stolen and taking 30k from 2nd level PC would be worth the risk for some hardened criminal types .
It could get very interesting for the PC's if they were not the picture of discretion.
The fun part about gems is there is also appraisal involved so values can fluctuate, heck if it was on or two really big gems they might run into a "black pearl" situation where none of jewelers would have much use for it depending on the size of the town.
Overall it sounds like it will make for "interesting" times for the PCs and will not buff them up too much.
I guess the main thing for me as a (RB)DM is that big gems attract attention as they are easily stolen and taking 30k from 2nd level PC would be worth the risk for some hardened criminal types .
It could get very interesting for the PC's if they were not the picture of discretion.
The fun part about gems is there is also appraisal involved so values can fluctuate, heck if it was on or two really big gems they might run into a "black pearl" situation where none of jewelers would have much use for it depending on the size of the town.
Overall it sounds like it will make for "interesting" times for the PCs and will not buff them up too much.