So I would spend the $100 bucks and hire someone (a team) to come in and do a deep clean once. Hopefully this cost can be split between all the roomies. Give them a specific list of problem areas so that they spend their time on those areas and not sweeping the same section of the floor you can sweep.

From there it becomes easier. I typically clean for about an hour of Saturday and Sunday. One day I'll do the bathroom. One day I'll mop. One day I'll move everything off the kitchen counter and wipe it down. One day I'll do the inside of the cabinets. Etc.

An hour is a good amount of time because it doesn't get in the way of anything, but it allows you to get stuff clean. You can get a lot done in an hour.

I would also choose to clean during times your housemates are around. Unless you are living with the rudest people on earth...or children... it's remarkably hard to watch someone clean and not help out a little bit.

Once the house is cleaner in general, it becomes harder to leave it dirty. I'll leave a dish in the sink here or some spilled water on the counter without thinking twice, but I would never for a second do that at my parents. The counters at there house is always spotless, which means I literally spray and wipe down those two crumbs and the circle from my drink.

Practically, here are some other tips:

Get vinegar. It cleans everything. Dilute it with water and put it in a spray bottle. Or splash a bit down all your sink drains once in a while and let it sit. It'll get rid of that stank.

Get windex. It also cleans everything (except real wood)

Get one bleached based thing for grout and the corners of your tub. I hate bleach but we have a can of it. I use Kablam foaming or something for the rest of the bathroom and it's alright. If you dont mind bleach, use that though.

Get a package of little heavy duty white hand towels. You'll save heaps from not using paper towels.

Get a good duster off of amazon.

Get gloves. I use little latex ones because we have a pack, but dishwashing ones would be fine. This is especially helpful when you are knee deep in the toilet going ew ew ew ew ew.

If you have a significant amount of floors, I recommend a real mop. If you dont, get the best sponge mob thing you can get. A swifter is not a mop.

Sign up for some bullshit mommy cleaning blog newsletter. Not only will you learn random cleaning tips, but you'll feel terrible about yourself; this bitch has time to raise two kids, handmake fucking cleaning solutions, go to church, and blog nonstop about it. What are you doing with your life? (lol)

Lastly, do the best you can to clean a little bit in between things. So like, you get home from work, relax, go to make food. While making food, clean the kitchen or sweep the floors or dust the bookshelves. Don't go crazy just literally 5 minutes here or there helps.