Walnut veneer plywood and economical do not go in the same sentence in my experience. There is typically no shop grade in walnut veneer. Typically A-1 or B-1 grade.
I had a heck of a time finding 3/4 walnut ply recently on my most recent plywood order. My normal supplier (Catawba Hardwoods near Marion) was out. Called 5 other suppliers who were all out and ended up finding enough sheets from Hood in High Point. A-1 veneer core (that looked more like B-3 with almost 100% sapwood on the back side...) for $180 a sheet after tax.
You might try calling Steve Wall Lumber in Mayodan. They didn’t have any a few weeks ago but were expecting a shipment about now and pricing is around $140 a sheet for 3/4.