If you're just starting out on your own for the first time, recently divorced and/or otherwise starting over from scratch again, one basic item you'll need is some kind of Tupperware. You've got to have some containers to store food in right?
Don't buy any brand new storage containers, there's no need to purchase a set of Tupperware, Rubbermaid, not even those el-cheapo Ziplock containers.
Buy food instead.
Finished with that cottage cheese? Don't throw the container away, don't recycle it, wash out the container instead because it just became 'Tupperware'. Done with that tub of butter? Wash that tub and use it again for storing something else in the fridge. The best containers out there for repurposing are the clear plastic containers used to package deli meats. They come in a variety of sizes and they're better than re-used cottage cheese containers or butter tubs and the like because they're clear, you can see what's being stored. They seal well, they're dishwasher safe (top rack) and most actually hold up better than the el-cheapo Ziplock stuff. BONUS: They stack well in the cupboard when not in use. BONUS #2: These containers are great for storing other items besides food. Tacks, nails, screws, batteries and much more can be stored, stacked and packed using repurposed deli meat containers.
One thing I would recommend you DON'T do is put plastic in the microwave. Nuking food in a plastic storage container prematurely shortens the life of plastic. The plastic stains (especially tomato sauced/based foods) and loses its shape and ability to properly seal over time. TIP: Always nuke your food on a real plate or in a real bowl, use paper plates only to cover your food to prevent splattering, but not to eat off of (unless of course you didn't wash the dishes last night and you don't have a choice....).