Well maintained duplex in B area help

[James Beam]

Looking at a couple 2/1 duplexes in a B area.   Asking price is $139k which I feel is very overpriced.    Here's the deal.   The seller has had the same tenants since 2009 and 2012 and has not upped their rent.   They are only paying $440/$445 for a grand total of $885.00.  He has never raised the rent in 15+ years because he did not want to deal with new tenants (ridiculous).   Of course, the rents now should be at least $600-$700 each.      Tenant pays utilities.

I expressed to the selling agent that the seller is trying to get a price that is equivalent to the tenants paying $700+ each for the property, cashing out, and having a new buyer to deal with 15+ year tenants in current leases who are paying very below market rent.      

The units are all brick, very nicely maintained and have newer roofs, hot water heaters, and furnaces.  They back up to a large green space in the back.   

Based on all the hassle of raising rents on these tenants at their lease renewal and dealing with possible new tenant screening (although I'm not sure where they would move to at that price),  what would you offer?