3d Cart Listing Page Customization

Hello.. I'm new to 3Dcart and looking for a developer with extensive 3Dcart experience for a simple fix to below 3Dcart project.. I'm looking to customize the ''[login to view URL]'' file in 3dCart which controls product listing pages.. need to use / pull existing variables to backward calculate and display a regular price when listing is on sale with and including options. as 3Dcart functionality only applies sale price to core / base price - it down not factor in options (our products are priced by options) - see below for simple fix to display a regular (non-sale) price with options when items is on sale. 1.) When I use the std 3Dcart listing sale function: input reg price, retail price, and sale price, 3Dcart will calculate the %/savings value on base price compared to retail price under variable [savings_percentage] - so here I can input values for example to apply 20% Off, and resp 20 will reside in a fixed usable variable [savings_percentage] 2.) as options are selected, the product sale price updates with additon of fixed option values (I would manually input the correlating 20% discount to all resp options).. so with the sale price and [savings_percentage] % variables I can calculate what the regular non-sale price would be with options and list on the page.. - this would be a simple workable solution to show what the regular price would be including options. 3.) I was able to get it working on a crude level via script - only I am not able to obtain the updating sale price when options are added or removed as my scrip coding exp is very limited.. the script code only pulls the original sale price value when page is loaded and does not update. The Sale price on listing page updates as options are selected, but the variables in my crude script do not update - if can pull the live / updating total sale price variable this would be a workable fix.. as can use to calculate and display reg/sale pricing with options on listing page, and maintenance would only require updating main sale price and corresponding option prices to have same % discount. let me know if the above is possible, and what would cost be to create the proper code/script to accomplish above noted functionality. -- also looking for a long term working relationship for many little projects over time as we work on our 3Dcart Store.