Is it healthy to eat frozen dinners daily?

I've looked into my finances and spending, and calculated that I spent roughly $300 a month on food, uming that I ate only $10 meal a day. This is too much for me so I want to start eating in, but strapped on time so I decided to just start eating frozen dinners. Are they relatively healthy, or full of preservatives? I just stocked my fridge with marie callenders, hungry man, and banquet meals. I'm sick of Ramen, so please don't suggest that..