In 90-95% condition, these generally sell for $150-$175. firstname.lastname@example.org
I only have some information for you. Any JC Higgins air pistol that begins with model 126 was made by Crosman air gun. Any model that starts with 799 was made by Daisy air gun. I suggest you click the Crosman link below and check the owners manuals to try to locate your pistol. Then re-post the Crosman model number along with the condition of the pistol to get an estimate of value.
If I am right the pistol was made by By Crosman for Sears under the JC Higgins name. It's a Crosman model 600. 22 Cal C02 pistol. Made between 1960 and 1970. Value is determined by the current condition. Without more information about the working and current condition it is not possible to set a value.