Glad you were able to get your frets in order! It makes a huge difference. Since I have started doing this I have really begun to see how many store-bought instruments have a very incomplete job of it. It's one of the major items that distinguishes between expensive and cheap instruments.

I have heard that diamond cutting files go dull over time. So far so good on mine, but I expect that at some point it won't cut well. I have heard that's not just a problem for the "inexpensive" files, BTW. Even the SM ones will eventually go bad. When mine does go bad, I am guessing I'll go for the FG rather than the SM.

I don't think there is a way to get nut files or crowning files cheap, They are purpose made precision tools--maybe the only ones you really need for electric guitars. That said, SM doesn't make them. They order them from a factory in Japan. I got a little better price getting mine from the Japanese version of eBay. I think Music Nomad has their own made. Fret Guru seems to have them made in Poland.