It's possible to actually stick to $2 - $3 per person if you shop carefully or make the favors yourself. However, you are usually pressed for time and it may be more convenient for you to buy the baby shower favors instead. To make the choice easy for yourself, try to match the theme of the baby shower with your favors. For example, if you are having a Western Barbecue baby shower, why not give out a bottle of barbecue sauce with a personalized label?
Edible or usable favors are best, and these can be purchased at very affordable prices. Women really love chocolate so why not a chocolate bar with a special picture printed on top? You could also give out cookie or brownie pops dipped in melted chocolate in your baby shower's color scheme.
If cost is an issue, there are ways to save money on favors. You can create your own favors easily by just purchasing themed boxes or favor baby bottles and filling them with candy, nuts, or bath salts. You can usually produce your own favors this way with very little work and each one will cost under $2 each. You can also use organza bags or translucent colored bags, which usually come out to only a few cents per bag. Fill these with edible treats or potpourri and print out your own hang tags or labels for effective presentation.
If food doesn't interest you, why not give out handmade jewelry (bracelets and necklaces are easy and simple to make), a laminated bookmark with a picture of a baby bump on it or your baby shower theme, or even a refrigerator magnet in a design that complements your theme?
You can get elegant favors premade and ready to distribute or you can get favors for very little cost if you are creative and willing to put a little work into it. Anything is possible here in the realm of baby shower favors!