Start with following sequence:
- tire balancing $10 - $20
- axial check, and fix $100 - $200
- replace rim $50 - $1000 (depend on rim brand, size, material)
You can find used rim in auto junk yard. They have lots of black metal rim for < $50, or alloy rim too. Look them up in Yellow Pages, and give them a call to confirm their stock. You have to go there personally to view the rim design though