Start with the Hare's Ear Nymph in #12. All you need to buy are hooks (a box of 25 quality hooks, cheap hooks have poorly formed eyes that create tying problems), tying thread in either tan or brown (either flymaster or 8/0), and Hare's Ear Dubbing in the package. Ribbing is optioanal and should be fine oval gold. This should cost about $10.00 for everything.
To tie the flies you listed you will need 2 hackle necks, one in grizzly and one on brown (or dyed brown grizzly). buy Grade #3 genetic necks (like I and all other profesional tyers do) because they will tie about 400 flies in the sizes #12 to #18 you listed. the #1 and #2 grade necks are only needed if you are going to tie hackled flies smaller than #18. A grade #3 neck is about $35.00 and you can find two half necks packaged in one package (a grizzly and a brown) for $40.00 for a real bargain.
Never, ever, use India dry fly necks, and never buy a Chinese neck unless you are going to be tying #4 and larger steelhead or atlantic salmon flies.