Our business model is, indeed, different than yours.

"other wise we will not make enough on replacement parts or sell as many new models."

Unless you're going to buy one of the higher end models that just came out, most of these "randomly" bounce around to room and don't clean the whole room on each run.

While it is the business model it can shrink when inflation, cost will wreck the housing industry.

Also TK model allows me to invest even by keeping my full time employment. 

I am building my investment analysis model to allow for quick and easy review of possible investments and need some guidance on some of the % values as inputs.

When they see their neighbors driving late-model, expensive luxury cars, they tend to ditch their paid-off entry-level Toyotas and Hondas for a huge car payment to drive a new Lexus or Acura.

And I assume their model to compare is towards the "best case scenario" when it comes to saving and investing....as in, the person doing it is actually disciplined to actually save money each month and invest it in sound investments....rather than go out and buy the latest iPhone....or a bigger TV....or a new car.....In other words, the person saving $500/month renting over buying a home actually takes that $$ and invests it in something that reliably and consistently makes $$.....and what % of the population fits that category?

Everybody feels that way.There's a woman I see on my way to work many mornings driving a late-model Ford Mustang convertible out of the makeshift gravel parking lot of a decrepit 1-family house in a poor part of town.

My Excel model calculates 40 different cap rates for every property.