Escrows often fluctuate greatly the first two or three years after a purchase or refi.  

Definitely a great city and only negative I see is the wild weather fluctuations. 

Currently reside in Midland, TX where the market fluctuates heavily depending on price of oil.

At this point I’m kinda tired of the fluctuations in the market so soon it’ll be time to move it to conservative funds.

And within same area prices fluctuate a lot between 250-550k for same size of house.

If you get an honest quote from one lender on Monday and another on Wednesday and rates moved down slightly during that time, of course lender A is going to seem more expensive; however the lower rate or pricing may be due to market fluctuations.  

I would like to get a mortgage on the house as the HELC is a fluctuating line of credit at prime +1 and would prefer a 30 year mortgage.

If actual use is $100 per occupant then I bump it 15 - 20% to cover fluctuations or waste.2.

The range is for whether or not the house already has duct work, model choice, and regional price fluctuation. 

Water leaks can be very expensive so you have to monitor readings and investigate any fluctuations.