I'd love to learn how to fly fish one day, but I'm not going to anytime soon as I dont need the financial equivalent of a daily cocaine addiction.
EDIT: And it's smart for Orvis to do this each year (SEE: financial equivalent of a daily cocaine addiction.)
It doesn't have to be expensive. There is so much good inexpensive(relative) equipment out there today...Granted you would have to put some money out front, but decent stuff will last you for years.
Incidentals do add up and get expensive...waders, boots, vest or packs, tools, fly boxes, nets, sunglasses(I consider sunglasses essential) etc...But they aren't all necessary to start.
Rod, reel, backing and line...a couple leaders and flies can be had for under $300, less if you shop real hard...And you're ready to fish.
And then there is always the used route. A lot of people feel the need to buy a new rod every year when the latest models come out...You can sometimes pick up last years $850 model for $300...A lot of fly shops do trade-in's and then sell the used equipment. You can sometimes find great rods and reels really cheap.
EDIT: This is all with Trout Fishing in mind...Saltwater Fly Fishing is expensive and I don't think there is way around that...Mainly because the cost of saltwater reels are high...A good saltwater fly reel cost more than the entire decent Trout outfit.