3rd party OCX buying/selling question

How do 3rd Party OCXs work.
If i use an OCX a bought in one of my programs and that program sells 1000 copies. Do i have to buy 1000 copies of the OCX or just one?

I'm asking because i see some 400 dollor ocxs out there but that would raise my final price and all.

Read the licence agreement for the control carefully.

But, generally you buy a developers licence for each developer in your team and that gives you the right to redistribute the OCX's as many time as you want.