Joanne,
One way to do this is :
Open "Master" worksheet and a "Customer" worksheet.
Find "Price" to be linked on "Customer" worksheet, in the cell that has the
price, select the cell,type "=", then select the appropriate cell on "Master"
worksheet,so on and so forth....
If these worksheets are located in the same folder, it will be much easier.
The instruct all users to select update links, when they open their
"Customer" worksheets.
Good luck,hth.