This is only my opinion:
Make sure you are meeting your daily protein intake from food and maybe 1-3 shakes.
If you have some expendable money left after that, then YES, aminos are a good idea.
Specifically, I would focus on either a BCAA mix, straight Leucine, or even HMB, as these benefit your muscles on multiple levels.
I will qualify my sentiments above by saying that (once my protein requirements are met) there are other supplements I would buy before investing in aminos, but to answer your question: YES, I believe they are worth it based on my past and current experiences.