It is never too late to embrace the arcane art of fly tying! Welcome back to the dark side of fly fishing, muhawha... !!!
I recommend staying away from the tying sets, they are based on philosophy of one size fits all needs; it never works out that way.
Treat your vice as capital investment - one that has a life of many years and thousands of flies, plus a significant resale value (you can also consider buying one second hand). The other tools are rather cheap in comparison.
As for the materials, consider what style of fishing - river or stillwater? and types of flies - dries, wets, buzzers, lures - you enjoy the most, make yourself a list of ten or twenty patterns you really need and break them down to a shopping list. Stick to this shopping list when you visit the fly shop - or you end up with a ton of very cool & sexy materials which you will never use.
And last bit of advice: fly tying is great way to let out your inner artist and gain respect of your peers, just don't expect it to save you money