You can count on me for shopping advice! I have become an expert at it! In order to do supplements you need:

1) quality and assurance of content and safety issues

2) you need to be able to afford them.

I shop around and find the best deals. At one time there were 3 of us taking many (my son for his ADHD). Hubby is only using a senior vitamin, flax oil, fishoil and Vit D--sometimes he uses ginseng but not always, now.
But I do consume alot of them, and many are costly types.

iherb has consistently improved to carry so many brand names, at wonderful prices, and then they give you discounts on top of it and free shipping ...you really cannot beat them IMO. The others like vitacost etc, are copycats.

Costco has also been a good spot for me, because they have quality products too. NatureMade for example. I get my generic SlowMag called Mag 64 there, for $5.00 a month! Can't beat that! (pharmacy there orders it for me) They started carrying the MegaRed just over a year ago. SAM's has good prices and so does WalMart. WalMart is a good local place for people living outside metro areas with few stores and who cannot get online. You can get quality whey protein in small containers at WalMart very reasonably, for example!

So yes, I feel obligated to share my $$ saving tips here. I do them myself!