I tie & buy...
I buy the stuff I'm too lazy to tie or patterns that take me too long to fabricate; poppers are an example.
However, the flies I fish most often are creations of mine or modifications of some well known pattern meaning stuff I'm NOT likely to find in a fly shop. THIS is why I tie and conveniently, most of these patterns have a simplified recipe of just a few materials.
When I first started tying if I knew I'd end up fishing mostly my own designs, I would have probably bought flies until I discovered what worked FIRST, before trying to tie every fly I saw in a book or fly shop. That MO results in over-buying materials that you may never use again...
As far as cost goes, as an example...
99% of the mayfly patterns I tie & fish with sucess are generic Thorax or Parachute patterns consisting of a poly wing, Microfibett tails, a body made of synthetic packaged dubbing and hackle (most often Whiting 100 packs) and I use Daiichi or Tiemco hooks.
So using 100 flies (because of the 100 Pack) as a standard to figure out the cost per fly, here is my generic dry fly material cost:
100 Daiichi 1180 Hooks - $35.00
Whiting 100 Pack Hackle - $22.00
1 Package Micro Fibbettes - $3.50*
1 Package Superfine Dubbing - $3.50*
1 Package Hi-Viz Wing Material - $3.25*
1 Spool of UNI Thread - $3.75*
* Will tie more than 100 flies
Total cost for materials - $71.00
Cost of materials per fly - $ .71
Everybody on here knows that you don't have to use Daiichi hooks, Whiting Hackle or even UNI thread so I imagine you could get that down to $ .60 or less and of course, most of the packaged material will tie more than 100 flies so that brings down the cost per fly even more.
Obviously this doesn't account for the start-up costs of a vise & tools, but that cost will be divided over 100's if not 1000's of flies. So as others have stated, tying your own flies can POSITIVELY save you money if you don't give up after the first dozen.
😉
One caveat is YOUR time. Based on experience and familiarity, I'd expect to spend to no more than 30 minutes of my time to tie a dozen of my generic dry flies. Based on that, I would spend about 8 hours to tie 100 flies.
If tying flies is something that takes valuable time away from your job or other responsibilities, then maybe the money lost or time spent tying flies is an important consideration...
However if you have the time to go fishing to try out the flies you tied, I assume it is a moot point.
🙂
Good luck!