We are already partnering on multiple properties so this is part of a larger plan, I just was wondering if there were other ways to think about the proportion of cash to equity.

My husbands aunt is selling it to us at a discount but is unable to do any sort of financing as she needs to sell it and get the funds.

A good condo board should be saving money for larger projects as they are known in advance (eg every 25 years you need a new roof). 

We had a plan to build a large real estate portfolio and then sell it in five years and divide the money.

This wasn't the most robust but the price point and them being sort of local (in Oregon) won the review. 

Phoenix is becoming a prime city for this sort of project Khaled.

At that point I am delaying retirement just to grow my accounts to a size larger than I need, that doesn’t make sense to me.I understand that by stopping those tax advantaged accounts I could be missing out on additional growth over the long run.

We have 40k in the bank and 100k equity in our current house (but we can't afford a larger payment on our current residence).

If you’re still sorting through your taxes, it might be worth running it by your accountant. 

I see some larger single family homes in areas that appear to be zoned R2 that, at least from a physical perspective, seem like they could work for this.