It really depends what you're learning or repairing, and how many different power requirements you need to fulfill simultaneously. Ian covered the common scenarios, but requirements can vary greatly as electronics covers so many areas.
Since you've been repairing electronics for a long time, how many power supplies and of what types have you used for that? How does, or will, the electronics you intend to build differ?
If you're really unsure what you'll be doing, then you can start off with a typical triple-channel power supply (e.g., 2x 30V@3A, 1x 5V@3A, with support for serial/parallel operation) and see what you end up needing as you figure out where your electronics interests lead you.