Been there, done that. It is a good way to make some extra cash. For me it was during college.

Restaurants aren't the only venue. Parks, parties, grand openings, etc. A gross of quality balloons will cost you less than $10. You could probably be up to speed on making them in less than a week.

Most people use a balloon pump I have always just blown them up. We still keep a bag around the house to entertain the kids and their friends with.

~ Dan