Anything is worth the money if you deem it necessary. Different equipment will provide different results. Too many condenser thingies (microphones) for digital recording can really sound quite harsh. That's where we use dynamic microphones and ribbon microphones. We might also utilize preamps that are transformer coupled in and out? Don't forget, there is a sucker born every minute. So when you get the cleanest and brightest recording in digital it can sound like crap. And then you need to scrounge around to take the edge off. So use more dynamic microphones instead of condenser microphones and you will have already solved most of your problems.
They are still trying to come up with software algorithms to mimic the nonlinear transfer characteristics of analog tape. Some folks utilize tube style saturation plug-ins. Others think they need analog tape style saturation. Some people want the cleanest, brightest, most neutral sounding equipment only to find out it's not what they really wanted. For $99, you could probably buy a for real analog tape recorder! And then you can have the real deal instead of a genuine imitation. That's kind of like a VW beetle tricked up to look like a Rolls-Royce. All that saturation software stuff is designed to mush up your recordings. There are plenty of other ways to accomplish that. Folks with $20,000 Pro Tools systems might want to spend three times as much for something because they think if they spend that much money, it has to be good. Problem is, nothing else was good that they did before they got the mushy plug in. Learning how to record and mix better negates the need for any kind of mushy plug in. So spend what you want if it's worth it to you. If you want some second harmonic distortion, take your audio file, high Pass filter it at 500 Hz and then double the pitch without doubling the speed. Mix a little of that back in to your other master file and you will have produced second harmonic distortion. See? Wasn't that simple?
I'm a simple engineer
Mx. Remy Ann David