If you are able to add an additional full bath, it sets you apart in the market big time! 

I should have ran the plumbing for it even if I didn't plan to add it.  

This is an additional step that would not be present for developing a lot where you are adding value.  

Part of that is adding additional cost for increase in building products. 

Make sure the estimates are very detailed (scope, SF, $/sf, schedule, etc) to ensure that there is a clear dilation between contract work and change orders.

Additionally, I’m curious about how this would apply to properties in provinces like British Columbia, Alberta, or Ontario.

That leaves an additional market demand of 780 units.

Whether the seller was open to a buyer commission or not, I wouldn't put an additional cost into any personal purchase.  

You and your legal, tax and financial advisors should review this transaction in greater detail, especially the PLRs, to ensure you understand the significant risks involved and are structuring the transaction as close as possible to the PLRs to mitigate some of the risks.

THEY ARE NOT LIMITED TO ONE PROPERTY.So, they can 1031 to 2 or more additional properties OR 1031 into a rental property plus a DST so that all the profits are used up in the exchange.