It is if it's your wife who is doing the collecting....
However if as you ask as a hobby no not really, there are of course both precious and semi precious stones to collect and of course quality of the stones plays an important part.
Depends also on how you intend to collect them, there are professional dealers who have to make a profit on their sales so these will obviously cost more.
Why not look for a collectors club in your area, or join one of the many online.
Read plenty of books on the subjec and learn how to use a good quality magnifying glass or jewellers eye glass. And know what you are looking at and looking for.