They can be made even cheaper if you reconfigure the mission goals to be taking blurry pictures of the moon.

Luckely Nasa stopped building telescopes and outsourced manufacturing to private companies. Now Nasa just do contracts

I don't know how much of a factor the cost of the components themselves were in the ballooning costs of the JWST, but if COTS could represent a major savings in cost without compromising the performance of the spacecraft and risking catastrophic equipment failure in the harsh environment of deep space, I'm all for it.