Keith,
Try this:
Items listed in Column A (1 through whatever), say 95.
In the next available column (say B) put your cost for the item.
In the next available column (say D) put the percent change ( an increase of
10% would be 1.10)
In a new workbook, sheet1 in cell A1 put customer's Name.
Below that copy Items in Column A (in above example) that this customer buys.
Label a Column Cost.
The formula that you enter in the first cell for the customer's cost will be
"=FirstWorkbookSheet1!B1*FirstWorkbookSheet1!D 1"
This will take the cost of item times the markup or markdown. This will link
the two workbooks. I would suggest putting them in the same folder to speed
up updates.
This way, if a customer's buy habits change. You can change the percentage
and print a new price list.
HTH :-)
PS
There is probably an easier way, but this is what I would do.
"Keith D.B." wrote:

Im fairly new to Excel but, Im wondering if I can create a price sheet that
is adjustable per customer. I want to print and give them to my customers
but, adjust the price by different percentages depending on their buying
history. My pricelist has several (about 12) sheets and about 400 items.