You will need to scale up versus doing houses to hit your numbers.   

As you mentioned this doesn't include any operating expense for maintenance, capex, vacancy, turnover costs, accounting, snow/lawncare, extermination, common electric, water, sewer and trash (or property manager).Excluding all operating expenses, except for taxes and insurance, when or if you move and rent the other side achieving $1,200 per side, you are then cash flow positive at ~$260/mo.

Would probably be better that I buy from a builder, I just find it less appealing buying at retail when I'm looking for cash flow...I'm spoiled from having a $1000+ cash flowing property already, so if I'm not hitting that number, it's not going to work for me.

Stories abound of people under contract (with numerous companies) to build homes and when they are about to close, the builder hits them with a huge price increase and it's take it or they sell to someone else for a lot more money. 

Increased housing inventory as new developments hit the market.2.

But in reality you might just want to think about using a standard savings account And taking a hit from inflation on the cash because the delta from the higher interest account to the regular account is not really that much on small amounts.

Office space has taken quite a hit lately, especially with the move to work from home.

You can add different ways to reach out to improve your conversion for owners you are hitting or you can increase the amount you are sending. 

The tenant understands that the property of the Tenant is not insured by the landlord for damage or loss of any kind (action of third party, fire, water, theft, vandalism, storm, heat or cold, electrical damage, pests, mold, accident, etc.), and the Landlord assumes no liability for such loss.

It is important to find something that was properly maintained, with modern plumbing, electrical and roofing.