Hello Searchers!

I have a deal I am negotiating in the Pet industry that I would like some help with. If anyone has navigated a similar situation I would appreciate your help and insight.

A business I am looking to purchase has achieved between $500k - $600k for 2018, 2019 and 2020, but the 2021 year was $997,000.
I offered a 3.5 x multiple based on the average of the 4 years. The owner is looking for 3.75 x based on the 2021 numbers.

How can I handle the negotiation so that it is fair for me and the seller?

Thank you.