A nice straight 24" diameter tree with more than 16 feet straight, that grades veneer, could bring $2k/tree.  

On the other hand, just an average tree that contains saw logs, may be $300.  

Walnut is very high now.  The last we cut 5 years ago, we averaged $650/tree, and were all about 24" trees, and varied greatly in quality.  

We had 3 buyers bid on our logs, on the landing, and bids ranged from $24k to $42k.   If you actually have trees from 24 to 48 inches in diameter, and are straight, you are sitting on a cash cow.