Buying my first Duplex and not sure what to counter with

[Amy Xu]

Hellol BP! I'm looking to house hack a duplex where I will live on one side and rent out the other side. Currently the house is listed for $225K and rents for $1,200 per unit (4 bd, 2 bths/unit). I started my offer with $170K and they countered with $185K no inspection or $210K with inspection. The duplex was built in 1950 and isn't in the best shape however there are tenants in each unit now. Owner says roof was replace 8 years ago... I'm not sure what to counter with or what I should do next. I'm worried since this is my first purchase that without an inspection I will be missing something BIG but don't want to lose this deal because a 4 bd per unit is a rare find. I've mainly seen 1-2 bedrooms in duplexes. Any thoughts what I should counter with?