Cosmic Ultra 20

If you can wait a bit, like November - May, you'll likely find *much* better value for money from end of season sales. If it were me and I had to buy something now for that temp range I'd probably get the Women's Kelty Cosmic Ultra 20 from steep and cheap for $150. If you're not a woman don't worry, women's just means it has more room at the hips and a bit more insulation. The Ultra version of the Kelty Cosmic has 800 FP down compared to the 550 FP for the regular version, that means it packs down more and is a bit lighter. If you sleep colder consider the Sierra Designs Mobile Mummy 15 from Kaviso for $150. This is the bag I use in the winter and I love it, IMO it sleeps a good bit warmer than it's comfort rating and the ability to use your arms or walk around without getting out of the sleeping bag is incredible for cold weather camping. Here's a video of a guy testing this bag out in 23 deg weather. https://www.youtube.com/watch?v=_-EMsTBMVKg

You're not gonna touch a decent sleeping bag for under $70. Heck, the Kelty Cosmic Ultra 20 is considered a step above budget, it has an ISO Comfort rating of 31f, weighs 2lb2oz but cost $140-$150 You need to reset your expectations.

If you're not into making your own synthetic quilt as suggested above, some sleeping bags come in both a right hand zipper and a left hand zipper and can be joined together at the zippers. Looking now I'm seeing fewer options that do this than before. ☹️ For example the Women's and Men's Mountain Hardwear Bishop Pass bags are left and right zipper respectively, but neither the Kelty Cosmic Down 20 nor the REI Magma bags seem to come in alternating zipper sides. Mountain Hardwear Lamina Eco AF comes in both left and right zips. It's a synthetic bag so it's cheaper but will be a bit heavier and take up more space in your pack than a down bag. But so would a MYOG quilt as described elsewhere.

I bought 2 sleeping bags this year. I'm just not a quilt person. However my summer bag (37°), bought a Chinese brand Qezer on Amazon under $100. My winter down bag Kelty Ultra Cosmic 20 also on Amazon for under $160. Now I'm not suggesting these are the best or necessarily for you, but I'm satisfied with both of them and don't feel that they broke the bank. However, they are both made of down, significantly lighter than synthetic, and pack down to a reasonable size for my pack.

First, I would say used higher end gear is in many cases better than new cheap gear. r/ulgeartrade is your friend and so is eBay and facebook marketplace. Second, the used versions of these will probably be better than new what you have… Naturehike 65L 40.96oz $120 -> this is really big, I bet you can get away with 55L if you really want to go UL -> you can get a used kakwa 55 for like $150, just make sure you get the right size Featherstone 20 Pad 26.3oz $109 -> neoair nxt, 16oz, three season all day, I got used on Facebook marketplace for $100 Ampex 2p 64oz $170 -> noooooooo. Used xmid 2p same price. Much better, half the weight at 32oz, if you want new than lanshan 2 Kelty Cosmic 20 Mummy 39oz $180 -> if you want to go UL, need to get comfortable with quilts -> new $230, used probably $180 -> https://hammockgear.com/product/burrow/

Kelly cosmic down 20f, not under 80$ tho, if your short you can get the women’s one at backcountry for like 110$.

I have the kelty cosmic down 20 and it it fantastic. Also about half the price of the ones you mentioned.

If its of any interest I have a kelty cosmic 20 thats only ever been used in my roof top tent. I can send it to ya if you pay shipping. If it works for ya you can use it for the hike or ill just sell it to ya cheap. Edit to add im in wnc in Waynesville

My first budget backpacking sleeping bag was a Kelty Cosmic 20. It was way heavier than I expected. A friend let me use their Naturehike Sleeping bag (not sure on specific type) and it was way lighter and more compact. I still use the Kelty for car camping, but it no longer goes on backpacking trips with me. My next upgrade will be an ultralight quilt. I got a used Gossamer Gear pack 55L off eBay that I love! I started with a Naturehike CloudUp 2 tent which was fine for the price, I have since upgraded to a Tarptent Double Rainbow (also used on eBay). Depending on the distance and weather, I will still take the Naturehike tent sometimes even though it is heavier. I like that you can use it without the rain fly on a nice night and just have the mesh top so I can see the trees and stars. My first pad was a Klymit pad from Amazon for $40. It works fine for warm weather. I upgraded to an Exped Duo 3R last year since I now usually backpack with my daughter or girlfriend and a 2P pad seemed easier. I also have two Nemo Switchback pads that I will carry on some hikes. I put them under my pad in the tent to prevent any punctures in my Exped and to give a little more insulation on colder nights. They are also great to pull out and use as a pad around camp when we are lounging before going to bed. Unfortunately, UL gear and spending an arm and leg kinda go hand in hand. All of my inexpensive gear was great to get me started, but over the last few years, I have been replacing them with lower weight, higher quality, and hence more expensive options. Along with being heavier, the cheaper stuff is just, cheaper. The biggest thing I have noticed is the zippers don't glide as easy on my cheap gear. This can be a huge annoyance when trying to zip your tent or bag.

As others have said, 80 dollars is a pretty low budget. If you want lightweight and compact you’ll probably want down, but the best budget-friendly, three-season down bag I know of is still around 180 dollars new (Kelty Cosmic 20). You might check out REI Resupply for gently used gear to get the price down a bit. Unfortunately, down is just expensive and backpacking gear in general is expensive. :-(

I love my Kelty Cosmic Down 20. It was budget friendly, especially for a down bag. It is a mummy style bag but is roomy enough. I am 5'11" and 230 lbs. I use an 11L compression sack for it while traveling. I have had it down into the high 30s and could have gone a little colder.