As someone who has just finished their second season fly fishing on a very low extracurricular budget (halfway through college), there is no doubt that many factors contributed to my initial financial leap into the sport. Online retailers, local fly shops, an older fly fishing mentor, and a ton of stubbornness all played a part. My mentor got me started on general info (line weights, terminology) and general brand recommendations. For my bigger first purchases (rod, reel, fly line) I had no choice but to shop online. Free shipping and endless sales on any and every baseline set-up was unbeatable. The smaller stuff (tippet, hemostats, flies) were bought at local shops to start making relationships and learning about the local waters. My first season was spent without waders, polarized sunglasses, a pack, a net, or even a real fly box, because at that point they were all non-essentials. This meant wet wading the Spokane River from October until March.
Although I still borrow stuff from time-to-time, I am more or less "kitted out." If I had bought everything that I have now (baseline everything) during that first leap into the sport, it would have costed $700-$800. No independent 17-23 year old man can confidently lay down that much cash on such a leap of faith. Luckily, I ended up falling in love right off the bat, was patient (stubborn) with the amount of gear I could afford, and stuck it out until I could afford to fish comfortably. This couldn't have been possible without online deals, local shop knowledge, and a super encouraging mentor who was always willing to splice on another section of flouro for me.
This is by no means to "toot my own horn," but more-so to say that there are many factors involved in initially affording this sport, and for me shopping online fit into that puzzle. As much as I wanted to "shop local," that wasn't a reality. Nowadays I definitely try to stop by the shop and consistently show my support through small purchases. However, if nothing else, this is just another encouragement to be a mentor to a younger angler, especially if they are low on funds.