Skylight should be substantially cheaper than that. Velux Actives in 2x4 are $1700 at Home Depot all day long and while I haven't added any, I've had three or four replaced for $200 per. I'd maybe find another quote on the roof. "Thinning out bamboo" is a fool's errand. Cut it down to nothing and keep an eye on it as it grows in. Garbage disposals are easy. If you have power under the sink you don't necessarily need a switch installed in the countertop. Just put one of these in the face of the counter. The hole saw you need is $18 at Home Depot and $5 off Amazon. srsly tho. Garbage disposals are easy. Ours died and I had the Costco replacement in and functional within two hours, and that included an hour going to Home Depot to get the parts I needed to install it.
Roof quotes were 13k and 25k without skylight. Skylight I had 5k because we're cutting in the new hole so leaving room for installation, drywall and attic work+insulation if need be. We're lower than our neighbors behind us by a good 20 feet. The space is weird, the bamboo actually is well contained, part of it was dying off and so I trimmed it to actually help it grow back. There's a 10 ft retaining wall behind it, and then someone's yard and house. It's a lovely green wall that maybe one day we'll exchange for something else but that's not anytime soon. We have the plug under the sink but need a switch. We could drill the countertop hole, didn't think of that thanks! I do think we could do the install ourselves, just a question of a switch for it.
I won't tell you to decrease your budget if that's how you're looking at it. I will tell you that you should have a lot of money left over afterwards. I've got thirteen skylights (because of course I do) and only two are active, but they're upstairs and they're great for moving hot air out of the house. Not sure it would matter that much to you but I recommend doing some cursory research before any purchase decisions. And I'm not saying "get rid of the bamboo." I'm a big fan of bamboo, actually, and find that it's predictable and well-behaved within parameters, those parameters to include things like "will shoot runners clear under a sidewalk." What I'm saying is it's a grass not a tree and cutting it down regularly is good for its health. Check with your local of course but one of the things I've had difficulty letting go of from my desert upbringing is "green things like to grow." "Prune harder than you think" is perhaps a better way to convey my advice. You can wait until December or January to keep what you have but if you straight nuke it before February it'll be lush and green by April. And I wouldn't necessarily drill through the countertop. Drill through the face of the cabinet below the sink. It should be 3/4" beech or whatever. Those pneumatic plungers are a pain in the butt to trigger accidentally.