That probe holder is very well made. If someone came to me and said "I need you to make this", I'd ask how many they want to buy at a time. I bet they would say "100 per order please". And I be Agilent order s100 of those every quarter, or maybe less.
So as a machine shop guy, it's going to take several fixtures to make that, and quite a bit of R&D time to get all the programming right. And I bet the tolerances are tight and I bet Agilent has spec'ed out some pretty rigid requirements for heat treatment, surface finish, materials, etc.
If I am the guy making them, you bet your ass I want $200-300 each if they buy 100 at a time.
Then Agilent has to sell it for a high enough retail price that they can discount it to their distributors. So it winds up being $1,200 on the Agilent home page.
Expensive, sure... but overpriced? Maybe - but if they weren't selling any, they wouldn't offer it. Must be worth $1,200 to someone. And definitely a lot of work went into making that.