I've heard that they can be pest repellents, but I can't say for sure. I ended up putting chicken wire around my raised beds. Otherwise the rabbits would just feast on whatever I had there.
The price isn't always the final criterion for me. I was trying to get my tomato plants to grow, but something happened and I lost them. I saw a plant at the store for $2 and bought it. I know I'll get more than $2 worth of tomatoes off it and it's fun to see it grow as the spring and summer progress.