S&S Duplex Cap rate - West Canada

[Adriano Aschenbrenner]

My family and I are looking to sell a duplex we have in the near future and I'm wondering to what extent cap rate comes into pricing. 

We are in Alberta, Canada, Side by Side Duplex. Currently NOI is $27900/yr and we want $475k takeaway for it (comps show slightly better SOLDs for 480-525k). That cap is 5.8%. For context, multi-units (I.e. a 12-unit I was looking at last month) are at 5.25-5.5% rate.

Am I not considering something here in our desired pricing? 

Thank you!

Adriano