Can you detail for us what modifications you needed to do? Special tools needed, time involved, etc. What's the cost savings against other available dew wipes when you factor in your modification labor?
For the outer window seals, I paid $19.45 each with free shipping from JCWhitney. And, for the inner window seals, I paid $18.10 each with free shipping from JCWhitney. Plus, you can always find Promo codes for JCWhitney and save a few more dollars. For the outer window seals, all I had to do was cut them to the same shape as the originals. I used a gray sharpie marker to trace the out line, used a dremel tool to cut to shape, drilled screw holes, and riveted on the other removable parts as my picture shows. I bought the felt from Lowes for $4.17 plus tax, which I cut to shape and glued with gorilla glue to replace the old felt. Here is a link to the felt I used:
http://www.lowes.com/pd_54164-255-4740095N_0__?productId=3034727&Ntt=felt&pl=1¤tURL=%3FNtt%3Dfelt&facetInfo=I already had the tools, glue, and rivets. So, if you have these already, then you can save a lot more over buying them from someone or some store on the internet. Overall, I'd say you save about 50% at least if you have the tools already and the time to make them.