Thanks for the feedback, everyone. The asking price for the duplex is $47k. If I was able to acquire it for $40k and bring in $800 / month, this property would meet the 2% rule, which suggests that it should provide a decent monthly cashflow. I know that its a general rule of thumb, but according to my estimated expenses, it wouldn't provide much cash flow with a 25% down payment, so it seems likely that I am overestimating expenses, hence the request for feedback.
Also the 50% rule suggest that my after mortgage expenses should be approximately 50% of my rental income. My analyses comes out to 63%... Again, it seems that I am overestimating expenses. If the 50% rule is applied, the property would provide some cashflow (~$118/door).
So here is the status of the analysis:
Purchase price: $40k with $10k down @ 5% = $164 / mo payment
Monthly rent: $400/mo x 2 = $800/mo with 10% vacancy = ~$8640 /yr
Taxes: $1151/yr = $96/mo (County assessor)
Insurance: $300/yr = $25/mo (Guestimated)
Prop. Mgmt: 11% = $1060/yr = $88/mo
Maintenance: 10% = $960/yr = $80/mo
CapEx: 10% = $960/yr = $80/mo
Water/sewer/trash: ~$50/unit/month ~ $1200 / year = $100/mo (Guestimated)
Lawn care: $75/month x 6 months = $450/yr = $37.50/mo (Guestimated)
Therefore, potential annual income = $9600; expenses = $6077; Expense to income ratio = 63%