Property has restrictions, how much discount to ask?

[Aater Suleman]

I am interested in a given area (Georgetown, Tx) due to the development happening there. I was looking for some unrestricted land that I can use for some local commercial like a container-based storage or truck parking.  I found this one property. The seller had advertised that property has no restrictions. I put an offer at full asking price (without an agent) and the property went under contract.

Title company has now found that there are restrictions. They read:

1. No Commercial RV Park Resort or Trailer home Park permitted on this property for any reason.
2. No Mobile or Manufactured homes permitted on this property.
3. At no time and for no reason shall any dumping of trash, accumulation of refuse, or
storage of toxic or otherwise hazardous materials be permitted on the Property. This covenant expressly prohibits pollution of any kind on or to the Property and prohibits
any person from allowing such activity to occur.

I still like the location of the land as a buy and hold, but feel it’s fair for me to ask  for a discount as it limits what I can do with it and limits my perspective buyers too. 

Any opinions of what’s a fair discount to ask? 10%, 15%?

More info: While the property is hot and had multiple competitive offers, I won because I offered a no contingency deal. Most other offers they got also asked for seller financing and suggested RV park as the common use (it’s a common product there).