NOTE: backup your tables (make a copy) before running any update/delete queries in case stuff goes wrong. there is no going back from these.
Step 1. have a table with your current price. we will call this tblInventory
Step 2. import the excel file with the vendor's items weekly into another table. lets call it tblProducts
Step 3. make sure there is a unique identifier (most likely ItemNo) that matches in both tables.
Step 4. create a query. put both tables into the query. join them by their ItemNo.
Step 5. double click on the ItemNo field from your tblInventory window.
Step 6. run it to make sure it works
Step 7. change the view back to design view
Step 5. make it an update query right clicking in the table area, and selecting it from query type.
Step 6. Add the Price field from your tblInventory into the query
Step 7. you will notice a "update to" section in your query show up. in the "update to" for the Price from tblInventory, make it tblProducts.Price
Step 8. Hit run and it should work
Step 9. Open up the new table
Step 10. Tools > Office Tools > analyze in Excel
Step 11. (in the excel doc that opens) File > Save As > prices.csv
I dont have Access open so this is all from memory. syntax may be off but I think its right.
More info at
http://www.databasedev.co.uk/update_query.html
If that solves your issue, please mark thread solved.
Thanks.