SWD Rates--Upton County TX

What are the going rates for SWD wells in Upton County, TX? We have a SWD well on our property that was drilled by the company that has the OGL to our minerals where the SWD is located. It has been used by the producer to dispose of salt water for on-lease production. The company recently contacted us to inquire about pumping off-lease salt water into the well. We have an attorney that will draft our lease, but we want to make sure we are not agreeing to lower-than-average terms per bbl. Per the RRC, the well has a max of 18,000 bbl/day. Thanks.