New hunting set-up

Hi - am getting back into bow hunting after about a 10 year absence. Had bought a new set-up back then and hunted again with it this year. It's dated, and along with the "itch" for something newer, I want to upgrade my equipment. Have learned a lot reading on here, but I have three basic questions that I can't find satisfactory answers to:
1. Used equipment prices look attractive. But, would I be better off spending 2X as much at a good bow shop to take advantage of their knowledge.
2. My old set-up uses a basic flipper rest - light and effective. Are all of these new rests worth the added weight, cables, micro micro adjustments and complexity to somebody who would rather be in the woods than tinkering with his equipment after it is set up correctly?
3. Same for sights - old set-up is a basic pin through a peep. Put it where you want to shoot and kill the deer.

As with EVERYTHING in life, it appears as though archery has become very commercialized. To me, it's more about getting into the woods, getting in front of a deer and shooting it. Of course, if I can greatly increase my chances of shooting one at longer distances, with less light and with cleaner shots, then I will be willing to buy some of this technology. So, any advice would be appreciated by this semi-newbie who was blown away by the racks and racks of products where the TM Hunter and 3-pin used to hang. Thanks