4-plex analysis, need help!

[James D Malone]

So I came across a 4-plex today which is very rare in my area, only a handful exist. List price of $160,000, 2 bed 1 bath units.  Has been on the market for over 3 months, owned by an older gentleman, looking to sell off his investment properties. This would be my first MFH so need some feedback!

This is my current idea, also note that the building is currently vacant and previous rents were provided by listing agent. I currently self manage everything and do most all of the maintenance/repairs. 

Purchase price: $125,000 (assuming offer is accepted)

Down payment: $25,000 (20%)

Financing: 30 yr @ 5% = $540 /mo

Initial rehab: $5,000

Closing cost: $2,000

1st yr Insurance: $1440

Taxes: $120 /mo

Insurance: $120 /mo

Vacancy: $150 /mo (8%)

Maint/Cap-Ex: $270 /mo (15%)

TOTAL EXPENSES: $1200

Rent: $450 /unit

TOTAL INCOME: $1800

Cashflow: $600 /mo

Cash on Cash: 21.5%

Here is a link to the listing if it may provide more insight:

Quadplex Listing

The unit is located on a decent street in a very small town (<10,000). Median gross rent of $530, median household income of $25,000. The city provides many jobs to the locals and surrounding counties due to heavy industrialization. 

Any thoughts or advice? Being my first MFH I am not sure if I am making all the proper considerations. Thanks!