I think supplements for the most part are a waste. I was a competitive power lifter prior to a rough motorcycle wreck and it makes me sick knowing that kids are wasting their hard earned cash on the crap from ads in muscle mags.
The secrets to getting in shape and not breaking your wallet:
Sleep
Water
Crea Mono - 5g a day, loading is a bunch of shi* and not necessary (remember more expensive is not better, you're just paying for marketing)
Whey - The only must have supplement (same as above, you don't need the most expensive on the market)
Multi-Vitamin
Meal replacements? Yeah, it's called canned tuna and .50 a pop at the grocery store.
If your dedicated to busting your ass at the gym then be dedicated enough to spend 15 minutes every night to cook chicken/veggies/fish and put it in zip lock containers to eat 5-6 meals a day.
I think all energy drinks are a waste of money too. You can buy off brand pure caffeine pills for 5 bucks a bottle if you really need an extra edge.
I don't like the topic of roids even being discussed. 99% of the population won't understand how to use them and use them to their potential. Too many young kids get hooked with the idea of fast gains. They read about how to cycle and what to take in recovery to negate any side effects but miss the most important part....
Where people screw up when taking them is the diet part. You need to be eating more than you thought humanly possible (clean, not cheeseburgers) while cycling, then eat almost as much post cycle to limit the loss of mass you gained while on the cycle.
I guess what I'm trying to say is diet is the number 1 part of getting big. Most people can have what some consider 'steroid' like results with whey protein and a perfectly fine tuned diet. It takes time and hard work, but I would spend as much time in the gym as I would tweaking my diet to see exactly how many calories and protein my body needs to maximize results.
I hope this helps a little bit. The one thing I'm trying to get across is that you should not spend more than $30 a month on supplements. Most are crap and a lot of money can be saved by a quick trip to the grocery store. Muscle mass is made in the kitchen and at the gym...not at GNC.