Importance of good stands

So recently I got into the budget high end audio game. I've started with B&W 601's and a Brio3 2 channel amp from Rega. I'm currently using a technics 5-disc changer so I'm not TOO worried about the little things right now since I know my poor source will make this unimportant right now. My focus is on stands, I being an audio "noob" went the cheap way and bought a set of $100 mdf stands so they've got no weight to them and they're rather tall. They've got spikes and bronze nib's to raise the speaker from them but they're still rather........un-stable. Am I going to hear any large problems from these? I don't want to have my money gone for nothing since I'm 19 and $100 is a full days pay. Any help?

Actually, MDF has its strengths. Unstable is bad, but only in a you-might-knock-em-over kind of way. Do they vibrate? That's the key question. One of my favourite pairs of stands I have are cheap little MDF jobbers.

Here's a simple test -- take 'em off the stands, put em on something else -- the end of a dresser or something (flush or a little overhang is fine), and compare them with the stands.

As long as you like the sound better with the stands, then you're fine.

They're not unstable really, I know they're not going anywhere. They're just very tall and not heavy at all. They're planted quite well because the spikes are easily a bit into the ply.

Are you able to add any weight to the stands? I know that some are capable of having sand poured into them to give them more weight. Not sure what your stands are like, but that might be a quick fix.