String making goes along with bow making, it is not hard to do with a simple homemade jig.
A spool of B-50 is cheap and all you need to get started if you watch the string making videos on youtube.
You don't need to plunk down the extra money for fast flight string material like DF-97, B-50 will suit your needs just fine.
I just looked for B-50 at the major suppliers, Three rivers only had 1# spools, you only need 1/4#, Lancaster didn't have any. Ebay has plenty shipped free for $13-$14 for 1/4#, mostly funky colors but that doesn't matter.
I checked ebay again but looked for Dacron Bowstring Material this time and found all the colors.