I’m a noob, but often what drives up lens cost is the complexity associated with making the image better over the whole field of view. Lenses have various inherent errors (called aberrations) that are corrected by a combination of complex surface profiles on individual lens elements and stacking multiple individual lens elements to cancel each other’s errors out. A scope likely only needs good correction near the center, where the user will be looking most of the time, while a camera lens needs good correction everywhere so the whole photo looks good when you view it later. Wider field of view makes good correction much more complicated and expensive very fast.

I forgot one thing: some places like REI offer pack rentals, so you can try them out on the trail before buying your own. Not free, obviously, so not the best option if you’re on a budget. Selection also may be limited. But it may be helpful in some circumstances.

There are so many good options, and it really depends what you are looking for.

Are you looking to go ultralight and want a very minimal pack with few extra features, or do you want a bit more comfort/luxury features at the cost of some extra weight?

Do you want a pack for a couple days (lower volume, maybe <40L) or will you be carrying days worth of food etc. (maybe >50L)?

I tend to do 1-3 day trips, so my 38L osprey exos is just about perfect. lightweight, but not quite what most would consider “ultralight.” but it has a few good, useful extra pockets and enough padding to be comfortable. I’m ok trading that bit of extra weight for those luxuries.

NO MATTER WHAT pack you choose, make sure you can try it on in person with full weight. If you have access to an outdoor store like REI in your area. If you ask, they should have weights to shove in the pack for you to try it. I cannot stress that enough, it is almost as important as trying on hiking shoes.