Hi Jim
While I agree with everything that Brian and Doug write, I want to add my advice. As mentioned, the key to getting multiple price lists is to use the Inventory module Alternate Price List feature.
Based on your needs, I would suggest that Invoices is a better fit for you than OrderEntry. Invoices allows you to print, revise and reprint invoices without having to post the invoice first, a major advantage over OE. It also allows you to store "pre-invoices" in an archive function, so you can segregate tentative invoices and final ones. Invoices has much more flexibility in the way your invoice can be designed.
If you are interested, email me at steve@sschwartzcpa.com and I will send you a much more detailed document I have written on the difference between Invoices and OrderEntry.
Steve Schwartz