I'm sure it is, but bulk line and spiral comes in at least 20' lengths so you will have alot left over. 25' of 3/16" is about $25 with some common nuts without armor. I thought I saw the spiral brake line wrap somewhere, but I can't find it now. Seems like I remember it was about the same price as the tubing.
Jim's Auto parts lists 4-piece brake line sets in mild steel for E-bodies for $59.00. $59 bucks for 4-premade lines isn't too bad.
Yeah, if the spiral wrap is not a big deal to you, the cheapest route is to get the tubing from a local parts store. Most have assortments with nuts already installed. Just buy a stick longer than you need with the right nuts and cut it to length and reflare it.