Too Good to be True!?

I'm thinking of making a significant investment. I keep crunching the numbers for this property with very conservative assumptions and I just cannot come up with many unfavorable long term scenarios(maybe I lack a bit on the practical side of things). I need some perspective from someone with experience. I have my agent, lawyer, and contractor lined up-I just have to pull the trigger.

Description: It's a 3 unit multi-family home that's a few blocks from a major University. It's kinda on the edge on the most desirable area for students but it's ok and relatively safe. The house is currently rented by a group of 7 students. They currently pay $2500/month+all utilities. I viewed property once and it was in working order but needed repairs.

Target Tenant: Undergrad/Grad students

List Price: 230k
My Estimated offer: 210k
Downpayment(25%): 55k
Closing Costs and Fees: 15k
Rehabbing Costs: 15k – Actually, I'm not sure, going with contractor soon to get an estimate

Assumed On-going Annual Costs:
Taxes: 2k
Insurance: 2k
Property Management(maybe):3k
Mortgage Payments: 10K
Vacancy: 1k
Other: 2k
TOTAL: 20k

Total Rent Collected(@2500/month): 30k

Net Cashflow: +$10,000

ALL the key metrics are significantly positive EVEN if I consider them at the listed price.
-Cap Rate
-Break Even Ratio
-Payback Ratio
-Operating Expense Ratio
-Debt to coverage ratio
-IRR
…etc

Someone help. I MUST be missing something. The main risk as I see it, is not being able to get student tenants. I would suffer a loss of 20k a year. But, demand in the area is relatively stable.