I have two things prohibiting them from being cost effective. The first is that they aren't available at all in my small town and I have to travel a distance to find them. The second is that over the years their price has steadily climbed. While the prices aren't horrendous the cost is getting closer and closer to $1.50 a packet unless I can find a good sale, which rarely ever happens.
I set about on a search to find the best price. So many of our UK friends talk about Approved Foods and I was wishing we had something similar here. They seem to get great prices on things often bought in bulk. If we have something similar here in the US I cannot find it. Vitacost didn't have what I was looking for, but Amazon did. Since I pay a once a year fee for two day shipping from Amazon (and yes we always save more than the cost of the one time fee because we buy text books for homeschooling and college on Amazon) I knew they would be my best bet.
I ordered 2 boxes with a 24 count each of seasoning packets.
Each box has a use by date of late 2014 so no worries there.
Cost breakdown when I finished was 76 cents per packet of broccoli and beef
and $1.06 per packet of fried rice seasoning.
(I did end up having to pay shipping on the fried rice seasoning and that cost
I've already sent home a couple of packets of broccoli and beef seasoning with daughter in law.
Now that the fried rice seasoning has arrived I'll be giving her a few of them, too.
I like having these on hand because I almost always have supplies on hand to pull together some sort of stir fry. Also by having a larger supply on hand should I need to pull together a double batch (when son and daughter in law are visiting for example) I can easily do so.
Of course, even when I add in the cost of ingredients...a batch of homemade stir fry will feed three of us for far less than the $30+ it takes for us to pick up Chinese in town.