For instance, I am sure everyone would love custom cabs - but will they pay you extra for them???

You could find for instance that the guaranty changed, was reduced to  a certain percentage, or removed all together.

For instance, if you invest in a house that is $100k, and your monthly rent income from it is $1000. 

In this particular instance, after a year of slashing prices, the seller has actually marked the property down to slightly less than what he paid a decade ago. 

For instance, if property tax is 1% and an apartment sells for $10MM, would the tax be $100K per year?

For instance if you plan to sell the business in 5-10 years a C Corp becomes more compelling.Typically a C or S election needs to be filed within 75 days after the start of the entity's tax year (which has passed if you formed the LLC in Feb 2018), but there is late relief available based on facts and circumstances if 'reasonable cause' can be substantiated. 

Before you buy anything ask yourself if that purchase will directly help you pay off your debt (for instance I just bought a part for my coffee maker to avoid me justifying buying coffee out) My husband and I have set a goal of no eating out besides one date night per month (cheaply, to keep the relationship alive) until the end of 2019.

Maybe it works out for you in that instance, but do you really think someone who will act in a fraudulent manner toward someone else won't turn about on you at some point?

Im in or was in a similar instance as you. 

Also- in many instances the higher priced properties are harder to make pay off as investments.