I tried to buy some of the P&B Time Delay relays in the late 1970s and they were about $40 at that time! And they weren't the fancy ones like these. They were just a fixed delay time. I needed about 8 or 10 of them but when I found out the price, I gave up on that project!
But I've seen a lot of very nice P&B Time Delay Relays in mil surplus equipment over the last 30 or so years and at $159 each, now I wish that I had saved them and put them on E-Greed!