Yeah, I ordered a pair of 712th myself. They are quite cheap (compared to release price) right now and spending 400+ isn’t an option currently.
I don’t really have a Place, where I could to that final mixing (maybe my bedroom might work). At the end, I do that as a hobby, and when it doesn’t break the car audio and is enjoyable on my iPad as well, I am quite happy 
Great to hear that you might inspire your son to be creative in that way too!