Sadly I do not have an answer for your question but I would like to follow this as I am interested myself. I have had some success of fb marketplace and kijiji but not really the same as the above. A useful tool I have found for this area is www.honestdoor.com.
On a side note I see your a contractor in my area. This year I wanted to try and get away from subbing out my Reno's myself and find a contractor who is capable of quoting and completing projects for me. My bread and butter so far has been adding legal basement suites so ideally someone who is skilled and knows the permitting process behind this.
Finding someone who invests themselves would give me even more peace of mind.
Yes I'm a contractor and have worked on a number of basement developments. You can get a hold of me and we can talk about what you have coming up, if you'd like.