You can grow that account to what ever you are comfortable with.  

Ultimately, it's up to you and your personal comfort.

So after being laid off a few times in the last 8 years I decided to get back into investing but this time focusing on buy and hold multi family real estate so that I could built wealth that could help me retire my wife who just had a long battle with cancer and survived , but is now back to work, and I want to give her a relaxing life free of all the stress of the world (by the way did I mention she is also in the mortgage lending field) so that explains the urgency to retire her from w-2 work ! 

Using Tools Like BiggerPockets:BiggerPockets has great "premium" calculators, but if you're comfortable with spreadsheets, you can create your own analysis template.

Market might be competitive but there is angles to stand out depending on what you are comfortable and able to handle, such as waiving an appraisal contingency, limitng inspection rights and time frames, closing time frames, allowing seller to stay-post closing, taking on difficult tenants, buying properties that might need repairs, etc.

Just make sure to research your local rental market and get comfortable estimating rehab costs.It’s a smart plan, and you’re off to a great start.

What about tenants that don't have smart phones or  aren't comfortable using mobile apps? 

Achieving a 15% yearly ROI in Tulum’s real estate market is exceptionally rare.When clients approach me wanting to invest in Tulum solely for high returns, I advise them to reconsider—unless they’re comfortable with a more realistic 5% return.

Just buy some basic LTRs and relax, they take so much less work....

There is a difference between being risk comfortable, and being a Kamikaze pilot.