These boards are old. The gentleman I got them from is 86 and he said he's had them at least 50 years, and they were in his grandfather's barn before that. I'd guess their every bit of 100 years old. You can tell they were sawn on an old rotary sawmill, the old fashioned ones with the big 4' diameter circular saw blades. The very rough texture would actually probably sell very well with the hipster "reclaimed" look everyone wants nowadays like this.
The thicker 8/4 boards I will keep and those will probably go into some maple/walnut cutting boards. My back can tell you that those 8/4 boards are heavy as all get out too!
The whole point of this purchase was to cherry pick what I wanted and sell the rest to fund other tool/wood purchases. I know that's probably heresy to many, but I'll never in my lifetime go through 500 board feet of walnut. It's not even remotely one of my favorite hardwoods.
Honestly when I have the time and extra cash, I'm always on the lookout for deals like this. They have been in short supply lately, but I've done pretty well for myself by being fastidious and researching before pulling the trigger.
The local sawyer who is a pretty good guy to deal with sells walnut at $6.40 a board foot or 20 board feet hobby packs for $150 that are 5-9" wide x 5/4 x 3-5' long. Another place I know of didn't even have any in stock this summer when I was looking for a piece. Some of these boards are about 12' long!
I'm curious why you would wait to plane them though? I've always been of the belief that if I dimension the stock and then sticker it properly and let it air dry/acclimate to my house/shop that I would have less problems with a finished piece moving versus dimensioning at the time of construction and introducing the potential for warpage.