I had this happen a few times. My response is, you have to pay for 3 years at the rate. It does not mean you work 3 years, you are paid for the contract,6 months,etc.
What happens, I had two say no way, one said yes. The two said no way, you move on.
I once negotatied something like 2x base rate for the duration of the non-compete period, and ended up accepting the offer. It was more than a decade ago, so the details are fuzzy now.
One of the nice features of this approach is there is a clear signal about whether the company intends to enforce the non-compete that does not require negotiation after parting ways. If they are not paying you, the expectation is that you have the ability to compete. From what I have seen, the uncertainty involved in non-competes (will it be enforced this time?) has a large part of the chilling effect.
What happens, I had two say no way, one said yes. The two said no way, you move on.