pjc5e

I think it would be more correct to say they are discrete in the time domain rather than digital. This is just semantic nitpicking though since digital usually implies discrete time. I never heard about continuous time digital electronics, it might be interesting to think about though it feels like an oxymoron.

Component prices will usually be a very important factor when choosing which components to use.

However, when you go into production and order parts from distributors, you will usually get special deals which can lower the price of your product. Problems can also appear if one of your single source components is out of stock, then you will have to wait (probably a long time) for it to get back in stock, choose an alternative (probably more expensive) component, or buy it on the gray market.

Edit: grammar and spelling

The problem of synthesizing a believable trumpet sound is way harder than creating a believable tube distortion. The trumpet is a complex system consisting of the the interplay between the horn and the lips, tongue, throat and lungs of player. Also, the way you interact with the trumpet is widely different from the way you play a piano, resulting in different musical expression.

Compared to that, the dynamic of a tube are pretty simple, though creating a truthful emulation of a full amplifier is still a hard.