With it being planting season, there are tons of places you can go to find cheap, healthy garden plants!
Try your local High School- many FFAs have greenhouses on campus and look to sell plants at rock bottom prices to raise money for their club. It's a great way to support your community and save money.
Prison Farms. Yes, Prison Farms. There happens to be one near me and they offer the best prices around. Like the FFA, it helps keep the money in your local community and helps pay for programs that give prisoners life skills.
Farmer's Market- another local place to try for great prices! You can also find a wide range of plant varieties here.
Craigslist- You never know what you may find here! Perhaps someone started 15 tomato plants, expecting half to die. Now they have more than they need and will happily sell them off at a buck each. It's worth a look!