how do you calculate the rate of return on a NOTE

[Pari Thiagasundaram]

There is a performing note that i came across and wanted to find out what parameters that other investors look for before purchasing.

Property is in Kellyville, OK.

BPO: $65,000

UPB: $18,560

Payment: $400/month

Number of months remaining: 45

Purchase price: $17,083.

Im using a financial calculator to calculate my return. N=45, PV: 17083, PMT=-400, My return (I/YR) is 2.75% ?. Not sure if it is worth buying. Can someone shed some light on this?