Why are Harbeth speakers expensive while its drivers are not.

Grannyring is right. When the Monitor 40 got its first rave review years ago, they cost around 7k, now the latest version is over 14k. It wasn't that many years ago, and I should have bought a pair, but the point is that even then, they performed at a higher level than other 7k speakers, and if they didn't, people wouldn't be paying 14k now.

:@quanghuy
You should research other speaker manufacturers. It might surprise you how many also outsource their drivers. BTW,most won’t give that information. Hint: If they don't say they make their own drivers then you know they don't!

It's impressive when a company designs and builds their drivers in-house, e.g. Vivid, but in the end, it's the result that matters. Some designers make an art out of sourcing the best blend of drivers and the best crossover to couple them with. 

As a former engineer, I worked on my share of proposals writing both tech sections and working on the cost bidding.

The price for a 'thing' needs to include the time to pay for the design, prototyping, testing, quality assurance, documentation- all this time is a cost to pay all the people working on just getting the 'specs' completed.

Then there is the time in setting up the plant to do the manufacturing run, and the time in plant to then start making the item.  Everyone on the line has to be paid.

And the plant has to be paid for -usually a lease to be paid to the actual property owner.  Then there are the utilities for the plant (lighting, electricity, water, maintenance).

Then benefits for the workers - they should have benefits, right?  Health Care, a savings or profit sharing plan, etc.

And then the actual profit for the company - that is why they are in business.

Don't forget advertising costs, travel to shows, meeting with distributors.

All those costs then get prorated into how many units the company thinks they can sell (along with all the other products the company makes).

The cost of a 'thing' has to factor in ALL those other costs - not just the parts.