Not sure what do you mean... You dont have to buy ... @curvefi

Yes, you do not need to buy CRV separately or lock rewards in order to receive CRV rewards for liquidity providing. However, locking CRV does increase the percentage boost for the rewards that you receive. When you stake in the gauge, the rewards that you receive are based on the amount of liquidity that you provide. If you lock CRV, then the rewards that you receive will be increased by a percentage based on the amount of CRV that you have locked. This percentage boost will increase the rewards that you receive for providing liquidity.

Yes, the percentage boost goes up when you lock CRV, no?