You will need 10% over the area you plan on tiling to account for cut off waste and then I would buy some extra tiles as back up if any get chipped or cracked damageI would also look and see where you can get clearance tile at.

The real reason is it was their last and only bargaining chip they had with me and used it as a means to control me. 

It becomes a bargaining chip to help negotiate a smooth move-out. :-)

Or maybe agree to chip in $100 (or some reasonable amount) to make them happy.The bigger issue is rent. 

Thanks everyone for chipping in their two cents.  

@Soh TanakaI’d chip in.

It looks like I may have to carry the brunt of the cost as I know that my aunt doesn't have the money to chip in ie "sold the land in the 1st place."

If it tests for minor contamination it's worth using that as your bargaining chip.

"Real life experience" would be something you could do right now -- how about you and 2-4 school buddies (or you and your brother) work like fiends (or, depending on who you/they are, get the 'rents to chip in) to raise $$ for the fund, which will be enough for the downpayment on a house that you yourself manage as a rental to other students (or y'all live in it and you manage). 

Also brokerage, many agents would be let go if the brokerage they work for found out they did something like this so if they're part of a larger firm you have that chip to play if you feel they acted shady.