I like SmartPaks. Most of the time, when you order buckets, you pay an "FOB" charge that is going to be about equal or more to the flat shipping, depending on how many different supplements you are buying at a time. So I find the individual packets cheaper, because if I'm paying the FOB, I figure all the freight charges and add cost per dose.
I like that Smart Paks don't go stale, are labeled clearly, and yes, the recyling is nice.
Also, I find that the fact that you can customize the dosage to exactly what you need means you can cut down on waste, and extra cost. Those little scoops that come in most buckets are easy to fill to the top, but if you have a horse that isn't 1200 lbs, then doing a 1/4 dose is harder to do consitently, but SmartPak does that for you, and it costs less as the dosage shrinks.
I found some supplements are actually more expensive when bought from the manufacturer, which you would think would be cheaper since there is no middle man, but in any case, if you do the math per dose/day and add your shipping and taxes, if applicable, then I find them to be a good buy on many things. (not all).
Also, in my Mom's case, I can ship her the supplements she needs, in clear marked containers and when Dad feeds (he is notorious for overfeeding all things and foundering the old pony) she can track the amount fed, etc.
Overall, I love it. Worth the shipping if you can't swing a free shipping coupon. You get more for your money when the supplement doesn't go stale.