Buy or no deal? - tenant with no lease

[Kammon Hiatt]

I'm considering purchasing a fourplex in Algona, Iowa.  It's an off-market property and the price will be about $82k to get it closed. It needs a new roof, paint, carpet and some general updating.  Three of the units are vacant (1 - 1bed/1bath unit and 2- 2/1 units). These unit previously rented at $480 for the 1 bedroom and $575 and $600 for the 2 bedroom units. There is one 2bed/2bath unit that is rented out to a long-term tenant for $200/month, which is less than a third of what it should be renting for. There is also NO lease agreement in place for this tenant.  How difficult will it be to evict this tenant in this area with no lease at all in place if they don't want to pay $650 in rent vs what they are paying now?  It seems to be a great value for the property, even if I need to spend another $50-70k in repairs and updates. The tenant without a lease is my biggest concern and it's a property that I would have to move in quickly. Any advice or info you have is much appreciated.