I wouldn't worry about it, buy a spool of wire and get a years worth of coils for a fraction of the cost vs buying premade coils.
I've purchased 5 (i think) different spools of wire from Fasttech, each costing me $2 of less since i started vaping and i'm still using them now. I've pretty much settled on my preferred gauge now, so it's a matter of buying one spool of that per year.
For the cost, you can roll your own coils, waste half a spool of wire(room to mess around making your own) and still be making a saving.