I'd imagine trying over and over again to create it himself would cost more than actually just buying it. Unless he's just like "Hey I know how to make it perfectly already." >_>
Considering that was the explanation in the old TV show (that the spiderbite gave him an understanding of what enzymes can produce a fluid like a spider-web).
Or hell, why not have it in his dad's notes? He learned how to make this tensile product, but he was killed/died before he could put it use.
--
TheRock ~ Slow dramatic zoom-pan. Doesn't phase the hooded man.
"You have issues." - MWC. Pot. Kettle.