It depends on the kind of research I am seeking.
I almost never go to U-Tube for anything other than entertainment.
For specs and "what's available", gun company web sites.
For price, I start with the Blue Book of Gun Values, review forum comments, look at completed auctions on GB or Auction Arms, or I simply follow my gut. I do often check what a couple retailers are asking for new guns on line.
I mostly follow my gut on the kinds of guns I usually purchase.
For historical information, I read books, review Gun Digests from my collection, review company catalogs, review or ask opinions from people I consider knowledgable or expert, or follow my gut. About two-thirds of the time, I rely on my basic foundation of knowledge, the Blue Book, and my gut.
I enjoy the forums, but my views of pricing is not significantly based on what the latest "bargain" somebody found which is generally often the only prices you see on forums or sometimes they are years old. Yep, I bought a Colt Diamondback or Pythons for $300.... me too, 20 years ago.
For day to day stuff, I prefer to rely on posts on TFL over some of the other forums even though I participate in some of those too. I especially like RFC for rimfire stuff.