Don't buy from some guy advertising in the classified and selling out of the back of his van. First of all, you don't know how old these M.R.E's are - they could have already past their shelf life. Second of all, they could be military rations - which are technically illegal for civilians.
It's always better to go with a trusted dealer. They won't risk their reputation by selling old or inferior product.
#2 Buy In Bulk To Save Money
While you can order M.R.E's individually, many times you can save some money if you purchase a case or several months supply at a time.
Since most meals have a long shelf life of 5+ years, it might be worthwhile to save money and buy in bulk up front.
#3 Store In A Cool, Dry Place
While these meals are hardy, if you want to keep them fresh and good, try to store them in a cool dry place like a cold cellar or basement. Don't store them in the your trunk in summer - that's recipe for disaster.
#4 Compare Apples To Apples
When you buy MRE meals you'll notice that prices vary across the board. That's because many manufacturers give you different food items in each package.
For example, one meal might include a premium entree, side dish, 2 desserts and 3 snacks. Contrast this with a package that only gives you 1 entree and a dessert and you'll see why it comes in at a lower price.
It doesn't mean one is better than another - it really depends on what you need. For example, if you are an active outdoorsman, you'll probably want to get the highest calorie MRE possible. If you're just storing some emergency food, you may want to save some money and get the more affordable package.
Bottom Line? Compare apples to apples and know what you need when you buy MREs. For a list of the top rated M.R.E.'s visit the MRE For Sale page.