As Larry mentioned, mentoring doesn't have to cost you anything.Any seminars where you have to pay, be very careful most are scams and only want your money. 

Because it takes repetition for people to remember things and you have to be top-of-mind when they encounter a potential client for you!

Originally only needed 80k of work into it but contractor that scammed me on a previous deal was also leading this one and ran off with 10k from here so that hurt.

While the allure of an already rented asset is nice to have, you've encountered the downside of an asset with under market priced tenants.It's too late now since you've purchased the building, but the typical process would be in your financial projections to account for removing the tenant at the end of the period, rehabbing the unit, and leasing the unit at market rent.

Whatever issues you've encountered in the past that wasn't outlined in your previous/current leases, now is the time to include them.

Search the BP for ADU appraisals to encounter numerous examples.

However, it's also likely that you encounter certain types of owners that have unreasonable expectations.

Has anyone encountered this issue or similar ones and I would appreciate any suggestion on how to properly respond to such request?

Fake It Till You Make it.Mind you, this is not the same as scam people.

Search the BP for ADU appraisals to encounter numerous examples.