residential demo cost

[CJ S.]

I have an erstwhile partner who is contracting the work on a shared flip because I am a newbie, but I am suspecting he may not be leveling with me on some costs. A seasoned flipper in Ft Worth told me that demo should cost around $.75 - $1.25 per square ft  making the cost to knock out a 442 sq ft wood floor in the basement around $552.50 .  My partner has told me to figure 10% of the total cost for all work done in a specific area - replace flooring, electrical, hvac, etc. that will occur in the given area. His figure to demo the basement floor is $2000 based on his estimation of the cost of ALL work that is conducted in the basement. Did I understand the fella in Ft. Worth correctly which means my partner is trying to milk another $1500 out of the basement floor demo?