Best twin mattress for a dorm?

I’ve been deep in the Reddit trenches for two weeks trying to figure out the best twin mattress for my new place. Honestly, I didn't realize how much of a nightmare it is to find something that isn't just a giant piece of overpriced foam or a springy mess that'll kill my back. Being a student on a budget means I'm basically looking for that Goldilocks type mattress lmao, affordable but won't sink in the middle after a month.

While I'm still debating between a hybrid and a memory foam base, I’ve realized the mattress itself is only half the battle. If you're in a dorm or a rental, you’re basically sleeping on a surface that has seen things. I'm trying to be realistic: even if I find the best mattress, it’s going to get ruined the first time I spill my late night coffee or if the room gets too dusty.

My Analysis of the Setup:

• The Luxury Foam route: Everyone keeps recommending the expensive brands, and they feel great for five minutes, but I’ve heard they trap heat like a furnace. If I'm spending $400, I don't want to wake up in a pool of sweat.
• The Protection Layer: I’ve been looking at this protector as a mandatory add-on. It’s got that deep pocket (6" to 15") which is useful cuz college mattresses are usually either weirdly thin or have a thick topper added. It’s marketed as breathable and dirt proof, which is great, though I’m always skeptical if waterproof actually means it sounds like a plastic bag when I move.
• The Budget Hybrid: These seem to have better airflow, but the cheap ones feel like you can count every single spring with your ribs.

However, for the mattress, I came across a few options like the Helix Midnight Luxe, and Saatva Classic’s mattresses, supposedly the most appreciated ones I could find on reddit through other threads. Most ppl recommend Helix for side and back sleepers cuz it cradles pressure points without letting you sink too deep, and Saatva for being a luxury hybrid with three firmness levels, top choice for those who want that hotel feel and good temp regulation. Even then ig Siena Memory Foam is a better option for students living in a dorm, since it’s more of a budget option rather than being a luxury one that would get dirty within a few weeks and ruin the entire feel.

I’m still leaning towards a medium firm hybrid for the actual base, but I’m definitely grabbing a protector first cuz I’m not risking my security deposit. For those of you who have this cover, does it actually stay cool? Also, if anyone has found a twin mattress that doesn't turn into a taco shape after a year, please let me know.