They tend to go for a premium over LE sporters because they are much less common. Their value depends alot upon the sporterizing features ( D+ted?, new trigger?, turned down bolt?, aftermarket stock?, drop floorplate?, etc) as well as the type of parent Mauser action (93,95,98?).
With these variables in mind 150$ to 450$. I picked up a nice one a few years ago, based upon a 95 Oberndorf action, Bishop stock, aftermarket med-heavy sporter barrel, D+T'ed, turned down bolt, in overall vg condition - paid 375$. Whoever did the sporting spent a lot more in equivalent today dollars.