It’s in a highly desirable area for families (good schools) but also close to businesses, transport, a major university, and walking distance to high end shops, restaurants, etc.

If this is for below-market rents and the tenants are under a lease then you would have to deduct the rent loss from their below-market rents for the remainder of the lease term. 

Seems like a difference worth shopping around for.

Secret shop them to find out occupancy and rates.

@Steven Gesis  this reminds me a little since this is exactly what the west coast marketing companies do they team up with the sellers of these homes in their markets.. but I remember one post when someone was complaining and the west coast marketer came on and said YUP sorry bout that we had a lot of complaints about that provider and we no longer use them.I thought well is that not just great.. they got all their fee's ( which are substantial ) and the poor investor is left holding the bag for the remainder of the investment.. and had to go through the west coast marketers learning curve...

I am currently an unemployed shop teacher.

I don't have onsite management so I should be OK with regards to that paragraph.I am a one stop shop...haha

Since your looking for a calculator, you may want to check out this ETSY shop.

@Carla Wehrspann a few of the cabinet shops in the area are pretty cheap.

Your current rate shopping period is limited to 30 days.