4 unit in AZ - Deal or No Deal

I'm looking at a 4 unit in Arizona that the owner would like $450,000 for. It is fully occupied for a grand total of $3475/month in rent. It is a 3bd/2bth, a 2bd/2bth and 2 - 1bd/1bth. The owner pays $255/month for water, sewer, trash. It has a pool (I know it's a liability but it's AZ) that is $85/month for maintenance. Management would be about $350/month. Taxes should be about $1800/yr. Insurance should be about $1200/yr. The current owner did put in a new pool liner, painted the exterior, and separated the electric for independent metering. I know he got a bargain on the property in 2017. It was listed for $350k then and he got it for around $280k. I realize he added to the value, I don't think it's a great deal at $450k. What do y'all think? What should I offer? Thank you in advance.