Looking at your wish list, it seems like your budget has about doubled. It happens…. Roksliders are really good at spending other people’s money. A lot of this list will depend on what failed on a person on their past hunts. For me it was boots…so they rank up there on my list. For other guys it may have been a subpar backpack. I’ll give you one guess as to what they’ll tell you is the most important piece of gear to upgrade.
1. IF REQUIRED - Rifle/Scope - $2-300 - like others have said, make sure that scope won't fog up or fail in any way. If in doubt, you can get a good solid replacement under $300. If yours doesn’t fog up and holds zero, leave it. Then spend lots of time at the range shooting said rifle.
2. Boots - $3-500 - I don't care what anyone says here, make sure you have a good broke-in pair of boots. And use leukotape liberally. As I was getting started on bigger, more backcountry style hunts, I learned this the hard way. In the past, I've walked away from animals because I knew my boots and beat up feet wouldn't take me to where the animal was that I glassed up. Not that size is everything, but I walked away from an easy 180"+ mule deer, knowing if I got to him and killed him, there was no way my feet/boots would get that animal out before the meat spoiled. I lost 6 or 7 toenails after that hunt. Get the right boots for the hunt you'll be going on, and break those things in with weight on your back, on the most uneven terrain you can find. Practice "sidehilling" in a roadside ditch if you have to. Get your boots soaking wet and walk around, tightening as needed. Sounds like you have some backpacking experience so I may be preaching to the choir here, but get some miles on those boots.
3. Binos - $800-1000 (Tripod - $80-600) I like to glass. I've hunted NW CO for 2nd and 3rd season rifle elk a few times, and in my 3rd year wound up killing a cow that happened to come running by me as I sat down to eat lunch in the thick timber. 30 yard shot, done deal. It was wild, and completely lucky. BUT, I had good rain gear, and wasn’t sitting back at camp huddled in the wall tent like a lot of other guys mid-day. Because I had good rain gear, I was comfortably hunting in the rain in low 40 degree weather. But in that same unit, I could glass for miles in some really neat country. Starting out, a good set of 10x or 8x binos would be my recommendation. I’m running Maven B2 9x45’s now and I love them. Used they were $800. Had 10x42 Vortex Viper HD’s before that. You can easily find these under $500. They did the job well for me for 5 seasons, but the Mavens are a big step up. Those Trinovids you have listed above will serve you well. I also have 15x56 Kaibab HD’s… I love these, but on a backpack hunt they usually stay in the pickup. I also have a Razor 85mm spotter that is in my pack pretty much every time I’m out. It’s not necessary for everyone, but right now I’m addicted to it. Also, keep an eye on the used market here to save some cash.
4. Pack - $300-600 - I've never used SG, but that pack you have listed will cover pretty much anything you want to do. Load it up and get it adjusted to fit you and you'll be happy you did. Don’t be afraid to go used here to save a few dollars too. MR, SG, Exo, Kifaru, they all make quality packs.
5. Rangefinder - $150-200 – I have a 10 year old Leupold RX-III… this piece of gear is getting upgraded this year. It can barely range out to 400 yards in good conditions. You won’t regret spending more money here, but you can definitely get by with something cheaper if you keep your shots under 4-500 yards.
6. My write in – ESPECIALLY if you’re backpack hunting, make sure you have good rain gear. Most of the big names are putting out good rain gear. Pick your favorite brand and buy the best stuff they make.
Another note, my first year hunting NW CO (2011) was 3rd rifle OTC elk. 2-4 feet of fresh snow in the mountains and nasty cold temps...little to no snow down low in the PJ and my tag was good for both areas. We had a wall tent camp up high in the snow, and split our time spending 4-5 days trying to cut tracks in crotch deep snow up high and 3-4 days glassing the PJ down low. Zero elk sighted that year... we were rookies.
Year 2 (2012) - same season/same area/same OTC bull tag. Few snow showers, most day time highs in the 40's to low 50's...spotted and got close to lots of cows, had opportunities at a nice bull but things didn't come together.
Year 3 (2015) – 2nd rifle/same area/leftover cow tag. Rain, rain, rain, rain... still hunted a lot in the timber and wound up killing that cow I mentioned above. Temps hovered around freezing, but I spent nearly every hour in rain gear.
Year 4 (2016) – 2nd rifle/Central CO limited bull tag - hunted up high, killed a bull at like 12,800' on day 6. Crazy year for warm weather and hardly any precip. This was an all-in solo backpack hunt, and I shot him 7.5 miles and about 3K feet elevation gain from the trailhead. 407 yard shot. I would have spent ridiculous amounts of money for a packer on this hunt, but couldn't get in touch with anyone permitted to work in this unit. If you're gonna use a packer, definitely line that up before you have a bull on the ground.
I hope that gives you a little taste of how varied these 2nd and 3rd rifle season elk hunts can be. You might end up buying gear and leaving it at home depending what the forecast is when season rolls around. $2000 is a lot of money to play with, and I guarantee your gear list will be better than mine was for my first couple trips to CO. I had a blast on a ramen and hotdogs budget. Good luck with your move.