[MOD REQUEST] product options full price

hi! as any knows when you put a price in a product option it must be a PLUS (or MINUS) price.
I mean with PLUS price, if the product costs 100,- US$
and option "A" of this same product costs 110,- US$
the PLUS price is +10,- US$

the problem is some distributors send their price lists with the complete price and is very annoying to recalculate the PLUS price.

I'm looking for a MOD to do that in the PRODUCT OPTIONS PRICES. any recommendations? thanks!

maybe this can be done as paid job?
i need this option for 1.5.1.2
regards