It depends upon the amount of money that you would be prepared to invest &
time available. I know of one small commercial stamp maker, that needs to
clear over £600 ( $ 1, 200 US ) each day for 6 hours work making about 25
stamps & he claims he grafts hard for that sum. However, art stamps &
signature stamps will cost his clientele more & take him longer than a day
( as he always needs to get the proof copy artwork approved before investing
his time & money next ).
Now if your really handle with a scapel or light craft knife, you can
practice what the Indian rubber stamp makers really do in India. They HAND
CARVE their own negatives from Indian Rubber blocks, but they can take
patients, time & considerable professional skill in doing so!
It basically returns to that starting point HOW MUCH money would you be
prepared to invest for such a project - get a realistic sum on that one &
the rest can be matched to meet than sum. Like everything else, the greater
the sum, the better the quality of the finished product.