Walmart has cast iron 2" weight plates on sale with free shipping
4x2.5lb $10 ($1/lb)
4x5lb $15 ($0.75/lb)
4x10lb $27 ($0.68/lb)
2x25lb $35 ($0.70/lb)
2x35lb $50 ($0.71/lb)
2x45lb $60 ($0.67/lb)
https://www.walmart.com/ip/17881811618
4x2.5lb $10 ($1/lb)
4x5lb $15 ($0.75/lb)
4x10lb $27 ($0.68/lb)
2x25lb $35 ($0.70/lb)
2x35lb $50 ($0.71/lb)
2x45lb $60 ($0.67/lb)
https://www.walmart.com/ip/17881811618