Dumbbells

= Weights

Good workout. Fun. Vanity.

Free Weights

Helps develop control muscles.

Dumbbells

Ideally, a whole range of equipment would be available, but when we start applying real world constraints, that's where dumbbells shine.

As Good

Head to head, each has their advantages. I believe that a barbell will develop pure strength faster, but dumbbells develop a wider range of motion and better control. Whenever I do a similar exercise on a bar, I can lift about 10% more than what I do with dumbbells.

Almost any exercise you can do on a bar you can do on dumbbells, but the reverse is not true. You can get about 150lbs on one dumbbell, for the equivalent of 300lbs on bar (330lbs if you accept my 10% assertion). There aren't many exercises you're likely to max that out, particularly if you're just starting.

Practical

A cheap set of plate base dumbbells is going to cost around $100 and will cover you for quite a while (more on this later). When you're ready to expand, you can buy plates as needed. An exercise bench is going to be around $50. So your startup cost is going to be around $150. An area of 5'x5' should be plenty when you're exercising (though you may need tall ceilings). And the whole thing will fold up into a small area when it's put away.

In comparison, to do a bar workout you'll need a bar, rack, bench and plates.