Hello,
A nice and simple user environment implemented as an Excel sheet can give you all the desired functionality. Using drop-down lists you will be able to select the origination /destination and zone, and enter the package weight and/or dimensions, while the code behind it will do automatically the calculations for the costs, possible discounts, and prices, as well as the comparison to the competitors. A button will allow you to make the final selection, and to preview the quote before saving it as a PDF, which then could be printed as a hard copy or send to the customer as attachment via email. Another button will allow you to make changes to the "database" records, that is, the table(s) of the wholesale costs, rates, destinations, competitors' rates, etc..
A few words about me: I'm developing VBA code for more than 15 years and I'm a trainer for Excel and VBA for 12+ years. As you can guess, I have created a plethora of Excel-VBA programs of any kind and difficulty level, for both training purposes and business.
Looking forward to hear from you,
Kind regards,
chriskerpini