BMW

I have a 2022 M240i. It has 16k miles on it. I found a 2020 blue/white 2020 M4 near me with 21k miles. Price is 60k trade value 44k. I am sure there will be a small amount of negotiation room here. Warranty quote is like 3k or so for 60m interested in how best to warranty this if I do buy it. I wanted a convertible to begin with but in 2022 I was not paying those prices and pickings were slim. Why should I not do this, talk me out of it. How much of a difference will it be between the two cars?