Wow, don't even get me started, most household cleaners are about 90% water, so there is no point in buying those pre-diluted spray cleaners, huge wast of money. I have 6 - 1 liter industrial spray bottles I bought at home depot and I mix concentrated cleaners into them and than use them around the house.
One gets a cap of bleach and filled with water, very clearly labeled bleach.
One gets a half a cap of pinesol or murphys oil soap or whatever floor cleaner i have and filled with water very clearly labeled floors.
One gets a cap full of mr clean multi purpose cleaner and filled with water oddly this one isn't labeled because it is either neon green or neon orange depending on what type of stuff is in there
One gets filled with a quarter of a cap full of simple green cleaner, this is an organic all purpose cleaner, safe for use around food and other areas, one jug of this will last almost for ever.
One gets filled with a quarter of a cup of distilled vinegar and a good squirt of dish soap, another good food safe cleaner, and if you don't add the soap, you can use it for windows.
The last one gets filled with blue windshield washer fluid you buy for 99 cents a gallon at the pharmacy. The stuff you use to clean the windshield of your car is ok for glass and mirrors and such inside your apartment, not as good as windex or the vinegar, but it costs 1/5th the price for about 4 times as much.
I know some of these cleaners are a bit redundant, and I could probably get away with just the bleach bottle and the multi surface cleaner, but each one is good at cleaning a specific type of spill or mess, so I like having them around.
Also, in terms of saving more money, don't buy as many papertowels, I have many kitchen rags and cleaning rags which saves you from having to use and waste money on paper towels. There is a definite hierarchy here, and you really need to have a lot of them because they can spread germs if not properly taken care of. You would be surprised how clean you can get most surfaces with just a damp cloth.
My personal hierarchy goes like this, first they are used to dry and clean dishes, after a couple uses they are then used to wipe up counters, never again to touch the dishes, after that they are put in a bucket under the sink either to be run through the washing machine or to be used on spills on the floor. When you wash them make sure you wash them with hot water and bleach so they are sterilized and ready to touch the dishes again, sometimes before I wash them I fill the bucket they sit in with hot bleach water and let them soak for a day before going in the machine.