Fixer-Uppers...how nice to make them?

[Jonathan Sowinski]

I am in the process of closing on an 8 unit building in a great neighborhood. The property has been poorly managed in the past and we feel that there is a lot of potential to tap into there.
Our goal is to renovate one unit at a time as them become vacant (it is fully rented as of now). I was wondering if anyone had any advise and or tools to use in figuring just how much to dump into each unit?
They are lower end units now (class D) and will never make it past mid-range (class C+ B-). The units currently rent for $525 each and believe they could fetch ~$750 if done right. The market is there.
Is it a matter of targeting a desired “payback” period and work from that? 5 yr @ +$225 increase is $13,500?
Any thoughts…
Are there any pros in considering leaving them in the condition they are in now? It would still be a good deal but I feel that it would be hard for us to keep our hands off of them.