What is the value of a Winchester 308 model 88?

More than you got. $800 for the .308 caliber in pre 1964 $1500 and up for the .284 and .358 calibers in pre 1964 (spare magazines are $100 each for all calibers if you can find them) The guns made after 1964 are not as good and all of them should run less than $700 depending on condition.