50% rule practice example...

[Sage Jankowitz]

So I'm not buying for some time, but I've been looking at some REO properties in my area to see what's available. I found a condo close by that seems to fit the 50% rule, but I just wanted to double check with the experts:

Price: $54,000
Rent: $1,100
Mortgage: $43,200 (w/ 20% down over 30 yrs)
Annual Rental Income: $13,200
NOI 50%: $6,600
Annual mortgage payment: $3,444
Annual Cash flow: $3,156 or $263/month

Again, just looking to see if the math was correct here and if you guys would pounce on a deal like this...