It is possible, but, I would say, not for those who do it as a hobby. You have to be prepared to purchase your supplies in commercial amounts and limit what you tie. For example, barbless dry fly hooks that I use are 11 pence each, bought retail in packs of 50. By buying them in thousands I got them for 0.8 pence each. How many people would want to buy 20 000+ hooks at once? Another example is thread, A spool of Uni here is around 2:50 UKP for 200 meters. Guttermann Skala (finer and stronger but still polyester based) is under 10 UKP for 15 000 meters. That makes it just over 13 pence for 200 meters, but you have to spool it yourself.

These savings do not make sense if your 200 meter spool of thread lasts over a year. They do make a lot of sense for a commercial operation. That is how the flies that the shop buys can be so cheap. Generally speaking, tying for yourself, and maybe a few for friends, you are not going to save on buying them.

By buying cleverly, I'm able to supply flies to shops at similar prices to the commercial tying houses. The USP is the flies are tied by someone who knows how they work. Not someone who is copying a sample and has never seen a trout.

Cheers,
A.