No one can render a professional opinion for your best interest
1. No location is listed in your comment. 20 acres can be anywhere in the world example 20 acres in New York City is worth more than 3 tier city located in South west Texas.
2. Till the entire property is evaulated by a Realtor or appraiser nothing can be stated.
3.. Recommend confer with buyer agent and appraiser who can provide you accurate information.
Lynn911 Dallas Realtor & Consultant, Loan Officer, Credit Repair Advisor
The Michael Group - Dallas Business Journal Top Ranked Realtors