If you want to bring newcomers to your garden, but you're short on cash, one thing you can do is check places where people are giving away plants for free.
A couple months ago, I looked under the "free" section of Craigslist and found an post for free grape hyacinth. This caught my eye because I planted some of these bulbs on my back porch at least a year before. I called the woman listed, and she set aside a grocery bag full of them that she thinned out in her front yard. My mom and I planted them along my fence and also at my front door. They will look much better next spring. It was a neat experience because I got to get free flowers for my garden and meet a fellow gardener. I hope to return the favor.
So before you go out to buy lots of plants, check online to see if someone is giving any away.