Also about to finish my first flip, it’s under contract. 

The best time to purchase is before they are finished.

This included updating the kitchen and bathrooms, improving the landscaping, and finishing the basement to maximize rental potential.

You can build in sound proofing, but honestly I'd go with 2-3 floors for each so you don't have the tenant downstairs complaining about the one upstairs walking around at night.For costs-it could be more or less than new retail-depends on finishes of each. 

(optional)Kitchen Remodel (2020): Updated countertops, cabinets, and installed new stainless steel appliances.Bathroom Renovation (2019): Added new tiles, modern fixtures, and a glass shower enclosure in the master bathroom.Finished Basement (2018): Added 600 sq. ft. of finished space, including a family room and home office.New Roof (2021): Replaced the entire roof with new shingles and added improved insulation.Landscaping (2022): Redesigned front and backyard with new plants, sod, and an outdoor seating area.Energy-Efficient Windows (2020): Installed energy-saving windows throughout the home.

I should add that there's stairs to the basement which is finished and it has a big area.

Time Commitment – How much time do you expect it to take to build a client base, and on average, how much time does a deal take from start to finish?

I just finished a total gut and rebuild of a duplex after a fire, and listed my 2 units a week and a half ago.

It was squatting down heavily but they finished it in one long Saturday with a lot of iced tea.

Lenders that would do that already went out of business, and/or stopped offering it, in 2022/2023.To get the 11% lender on board, you'd needing to be looking at a property with vastly more significant upside than a standard ho-hum annual 5% rent increase.A 30% vacant mismanaged apartment building would be an example of where the 11% lender would step in, and ACTUALLY make it to the finish line.What you are looking at right now is someone that's going to garner 20 applications with the hopes of finding 1 or 2, with enough upside, to actually fund.