A lot of people try to make $100+ profit per door, each month.

But there are companies out there , they operate by quoting extreeeeeeemly high prices , their salesmens commission is based on the profit on the job . 

Builders profit is on the end.

These loans are the same work as a bigger loan for less profit.

Massively increase rents and sell at enormous profit.

So the owner also makes a monthly profit.

Many investors are too short-sighted to do this math and fail to understand that it's often foolish to focus soley on top-of-the-market rent as it can actually be more profitable to accept less than max rent to keep a good, stable tenant.

However, none of the below qualifies as acceptable:just put the same as last yearnah, I did not make any profit last yearI guess between $10k and $20k per property, or maybe $25kI dunno, how much expenses are normal for my business?

Plus your numbers as to profitability of the MHP are way off.  

Ofcourse you would because you could turn around sell it for a $40k profit.