First of all, the price is because they are using the highest quality parts available.
3D printed parts is one of the main reasons why they continue to get better.
Sure, 3D printed parts are not as strong as injection molded parts, but the 3D printed parts for the Prusa printers never fail in my experience.
They have a huge printing farm that prints the parts for new printers, so they see every issue that might come up with their printers and learn from it.
They could save a lot of time and money by using injection molded parts, but it makes it harder and more expensive for them to test new improvements.
Plus when they come up with new improvements and it only requires new 3D printed parts, they release it for free, so the user can print the parts themselves.
Prusa has the most friendly user environment I have ever seen. Every time they come up with an improvement, if it is printed parts only, they release it for free… If it also requires hardware, they sell it for a reasonable price.
How many other companies offer upgrades at a reasonable price (or free)? Most companies want to sell you a new model.
Also don’t forget, everything they do, whether it be hardware design, software, or 3D models, they always release it as open source. I have the highest respect for this company, as they are clearly community oriented.