I hope this does not come off wrong, but if you need to ask what to spend money on, you should probably save the money until later on. When you need an item, you will know it. Wait until you are limited by your tools, then acquire more.
For example, if you are playing with microcontrollers: you will probably need a multimeter and a logic analyzer early on. Then problems will arise in the "analog domain" (bus contention, logic levels, etc.) and you'll really benefit from a storage scope. If you start playing with RF stuff, you'll want visuals of the "frequency domain" and might save up for a spectrum analyzer. And so on...
Figure out what YOU need, and when you actually need that tool, buy it. Things get better and cheaper as time moves on, so there's little reason to buy stuff before you have a use for it.
-Farrell