Yes, that's true, it's the "prudent" way to order stuff, except I can never find all the things I want right now that are also in stock all at the same time at the same place. Eventually I just gave up and ordered what I needed from whoever had it when I needed it and then just bit the bullet on the shipping charges. I'm too old to keep waiting for the best deal. I take whatever I can get, whenever I can get it now at a fair price. Next week I might be dead and won't need it anymore and so it makes no real diff to me or my heirs.