The 2006 Tahoe 2500SRD was manufactured by Thor. Blue book values for this toy hauler are available online from NADA Guides by using their section for RV. After selecting Tahoe by Thor Industries (California), then select the year. Afterwards you are provided all models of the Tahoe Toy Hauler manufactured this year including the slide out 2500SRD.
NADA Bluebook Values are provided as follows:
Low Retail - $7,950
High Retail - $9,600
Prices should be increased for additional options since this is a base value.