What Would You Pay for this MultiFamily Property?

[Will K]

A four unit quad-plex, built in early 1900, renovated/updated over the years. Each is 2BR/1BA, about 850sq ft each. Utilities are separately metered, owner pays for water/sewage/trash. Monthly rent per unit is $525. Assume no more than $3,000 in repairs/upgrades needed at purchasing. Assume roof is good for another 10 years, appliances are good for another 5. Property is in a B/C+ area, within walking distance to bars, restaurants, historic downtown, small grocers. Assume buyer would put 20% down at 4.5% APR.

Other facts: Located in an urban area of about 50,000. As per Wikipedia, population growth by decade has only declined twice in the last 160 years (by -0.7% and -3.0%) and has increased on average over 10% per decade (i.e. no reason to believe vacancy rates in this area would be any different from the national average)

What would veteran BPers offer for a unit like this? What about if all the same scenarios were in place, but rents increased to $750?