I cook for myself.

I also worked as a cook at a hibachi/stir-fry place for about 2 years so I know my way around the grill, stove, whatever. When I buy food I can typically eat for 1-2weeks on 20 to 60 dollars. Mixing foods works, When you buy meat, and don't think you'll be able to eat it fast enough, portion it out and toss what you think will need to be saved to the freezer.

Also Stirfry and rice are awesome.