Creating a Price calculator using drop down boxes for multiple BOM's

I am trying to create a price calculator for a particular product line which has multiple sizes and configurations. I would like to use drop down boxes so the user can select the size, type and attachments which will be narrowed down by the previous selections. I would like the formula to be able to calculate the cost of the components based on the selections made. Based on some research I believe this can be achieved using data validation, indirect function and the vlookup function, however; I'm not quite sure how to go about this. I have attached the document I have started for reference. Any help would be greatly appreciated.

Thanks!

Not sure what your true problem is, or is it many? In the future, I recommend you isolate specific issues, as this is too generic that I (and I'll say other posters) don't know where to start.
For function help, just use the Excel help documents (hit F1) - they are really good and provide examples much better than we can post in this forum. If still confused, then post in here.
It also seems you are looking to create dynamic data validation lists. A quick google for 'data validation list dynamic' brought up many webpages that can explain and even show (with videos) how to achieve this goal. I thought this one looked good:
http://www.contextures.com/xlDataVal02.html
but Chandoo is also a good source for Excel help.

I have watched a few videos and tutorials and I believe what I am looking for is a way to have one cell with multiple lists based on the specifications selected from two or more other lists.
My application is my company makes Chain lifting slings, they come in 6 different sizes with either 1, 2, 3, or 4 legs. For each type there are between 2 and 12 different top and bottom attachments that differ based on the chain size and number of legs. What I am trying to create is a form with drop-down list that will be narrowed down based on the previous selections.

Hopefully this narrows it down a little, thanks for the help!

Thanks for clarifying. It sounds like what you are describing exactly matches the link I provided. In that link there is a selection for Fruit or Vegetable and then the second list is different depending on whether you chose Fruit or Vegetable.