Personally I would suggest picking up quite a few flies from cheap places like fly shack and stuff until you get your casting down and such. If your budget is tight at the moment that may be your best option. The flies may not last as long as some that you would buy from a commercial tyer, but if you're losing them in trees anyway it probably wont really matter.
You would be better off in my opinion picking up a few of these from a cheap online place.
bead head hares ear size 14
bead head hares ear size 16
bead head pheasant tail size 14
bead head pheasant tail size 16
caddis larva size 14
caddis larva size 16
prince nymph size 14
prince nymph size 16
In my opinion you can catch trout on any stream in America on those. If you have the option get the hares ear in black, natural, and olive.
Once you get your casting and such down to where you aren't losing any, mix in a few from commercial guys and such.
I'd say average nymph price on custom stuff would be between $1.50-$2.00. One big benefit would be you can tailor make them to exactly what you want. But right now, you would nearly be throwing away money until you gain control of your casting.
