Beginner Collector: Magic the Gathering?

What are you collecting for? To have complete sets or cards for playing or both? I did both for many years and finally sold off most of my set collections, although I still have a few foil and non-foil sets around, complete or mostly complete. I can tell you that collecting the sets can be a lot of work as there are well over 10K cards in magic now. Collecting to play is different, but still a lot of work, but it can be great to pull out a good binder and start trading!