Javascript and PHP price calculator

Hi All, I'm looking to make a price calculator for my custom t-shirt printing site. We would design the content and look of the price calculator so really all we need is someone to make it functional. Here's a basic version of what we're looking for: [login to view URL] We would probably just like to include more shirt & apparel options as well as the option to get a quote for multiple items. So instead of just getting a quote for one design on one type of shirt the customer would be able to get a quote for 2 designs on different shirts or the same design on different types of shirts (e.g. men's and women's shirts) In addition to this we would like to allow for this to be integrated with a back end admin section where we could add/update apparel styles & pricing. Down the line the goal would be to also make this part of an order submission form, and we will be seeking to be making improvements over time. So we are looking for someone that would be available in the future for follow-up work. In the initial bids we are just looking for a bid for this project and then we would just like to know what your future hourly rate would be if we needed to come back for improvements/changes. Thanks so much for your time! Best, Thomas Ultimate Shirt Co.