First deal analysis help

[Emma S.]

Hi, I'm looking to make a cautious entry into REI with this potential first SFR purchase.

Cash purchase price $22k (no rehab needed at this time)

Rent: $550 (current tenant is midway thru a 2 yr lease thru 6/2014)

Gross income = 6600

Expenses:

Vacancy (1 mo) 550

Taxes 297

Insurance (estimate) 400

PM (12%) 792

Repairs ( ?) 1000

Total expenses = 3039

NOI = 3561 Cap rate = 16%

Questions:

1) What is an appropriate % to use for maintenance? I just randomly used 1000 for this calculation although I'm setting aside reserves of 5k (planning on doing a few things like windows and paint in June).

2) How much total reserves is appropriate to have on hand at any given time? Or is a decent line of credit good enough?

3) Are my calculations right?

Appreciate any feedback. Thanks!