They measure 4 by 5 feet, so we can estimate they are probably made from a solid chunk of titanium that was at least 20 cubic feet or almost 5,000 pounds. That would be nearly $150,000 in raw material and probably another 5x that in processing (guesstimating cost per cubic inch of titanium removal).
Either that or they were specially made castings, which are similarly expensive in low volume, if not more.
Wouldn't you be able to recover most of the removed titanium, amortizing the majority of that guesstimated materials cost? Processing likely remains expensive, however.
Printed metal has huge issues with heat, and they just switched from aluminum gridfins to titanium because of the heat. I seriously doubt that they’re usung additive techniques here.
You are also dealing with low volume fabrication which means setup and tooling costs don't amortize across many components. I wouldn't be surprised if they cost $1M each.
I'm also a bit surprised the grid find are so pricey, they seem pretty small? Not that I really know how much titanium costs to buy and machine.