HELP! - Shipping calender

Hi Guys,

I am very new on here, so Hello to all! I hope I have posted in the right forum topic.

I am currently creating a spreasheet by where I can accurately calculate shipping costs for items which can be shipped in our 'stock' materials. I have collated all the raw data and am now trying to create an easy to use document where by the user can enter the box size (with fixed value of the cost of these attached), enter a variable cost for materials such as bubble wrap and then select the rate applicable to the zone its heading to obtain an overall final cost. Preferranbly using a drop down menu

I have tried Data Validation and VLOOKUP formulas and don't appear to be getting anywhere, I just keep getting errors when I try and create a VLOOKUP table with the variable information and I cannot combine my box type and cost with Data Validation.

I have attached a copy of the spreadsheet I am working on, any help or advice would be appreciated before I tear all my hair out and/or the computers heading out of the window!