I bought a 2-row planter for 75 bucks for my food plots. It took and 10 hours and another 75 bucks worth of nuts/bolts/special tools to get it fully operational. If you are patient and can look around, you might find a deal like that.

Don't be afraid to buy a planter even if everything is completely rusted together. I did. Just use a wire wheel, penetrating oil, blowtorch, and the electrolysis method of rust removal to clean it all up.