Most people know you can buy wine by the case for a discount. Most people in fact seem to be aware that even chain grocery stores will give you a discount on as few as four bottles of wine. But once you find a wine that you really like, perhaps a wine that you'll enjoy for a long time and that will improve with age, or possibly a table wine that you like well enough to include frequently in your menu planning, the thing to do is to buy your wine by the case. Now, don't start thinking that buying by the case isn't for you, or it's too expensive. It's really quite easy, and no, it's not really expensive. In fact, if you buy wines you would buy and enjoy on a single bottle basis by the case, you'll save money, and time. This part is important, and you might not think it needs to be said, but it really does: don't buy a wine by the case unless you've tasted and know you'll like it, and that you'll like it again.
Keep in mind that you can often buy by the case even when it's not apparent that cases are available, or at a discount. One of the first Washington wines I tried and really really liked was a Red Diamond Shiraz; it was the first Shiraz I'd had from anywhere other than Australia, and I liked it enormously right away. It was lovely on its own, but it was really enhanced by food—and it really enhanced a surprisingly wide array of food. At the time, I was living in a fairly isolated community, and doing a fair amount of my shopping at a small local market—but it was a small local market with an excellent and engaged wine buyer. He was delighted that I liked the shiraz, and had no problem ordering a case for me—and giving me a very substantial discount. That simple request led to him suggesting a few other local wines to try. Even though I've moved, I plan to return and buy more from him for that reason.
The large chain grocery stores all offer 10% or more off on case lots, and they offer the discount on mixed cases, usually. In some cases, the store will apply a case discount on top of a sale price. I've also had store wine buyers spontaneously offer me a special deal as a repeat customer—keep in mind that wine buyers are wine buyers because they like wine. If a wine buyer points out a special deal, you should listen; they tend to know a good price for a good wine. State liquor stores do offer case discounts, but it doesn't seem to be standard across the board; I'd ask at your local store. I also note that in Washington, the state stores do have special case sales. Don't forget Trader Joes, or the warehouse chains.
You can buy cases of wine at a discount online too; they tend to offer discounts on single cases but there are a few online retailers who do offer 10% discounts on mixed cases. Many offer free shipping with a minimum purchase, and almost all of the online wine retailers will have a special case sale on a different wine on a regular basis. Watch out for online coupons too; a number of online retailers, including those that specialize in Pacific Northwest wines, offer coupons. The online wine clubs can offer fabulous savings as well, sometimes as much as 30% or more, on case lots to members.
If you're buying wines to age them, that is, with the plan of buying a case now, to drink over the next five to ten years, you might feel it in your pocket now, but in terms of future costs, you could be paying possibly as much as ten or twenty dollars a bottle less than the same wine will cost you in five or ten years. This is particularly true with the initial release of ice wines; even a half case is a worthwhile investment. It's also a lot of fun to trade Washington wine with people from Australia, South Africa, or Europe, where they don't really have a lot of Washington wines, even now, to try. I also favor buying Washington sparkling wines after New Year's, when they tend to be on sale with amazingly good case discounts. Why restrict sparkling wine to New Years? If you buy a case at a fabulous discount, you can enjoy sparking wine with your summer salads and spring desserts.
Finally, I'd like to make a special plea for going to the Washington wineries, trying their wines, and buying a case or two of whatever strikes your fancy. Depending on the winery, and when you visit, they often have temporary special sales on case lots, and a number of them will offer a case discount on mixed cases. It can be a lot of fun to try a few wines, and buy a couple of others to try at home, based on the winery's recommendations. A number of the larger Washington wineries have their own wine clubs, with regular special tastings and discounts. The winery wine clubs can be a lot of fun, and many of them select wines that are only available in limited quantities and offer them exclusively to their wine clubs. If you have friends with similar tastes in wines, buy a case that you share; twelve bottles can be split, easily, between two, three, four or even six people, and it's a lot of fun to sample wines with friends. The wineries, especially now, need our support, and while you might not get a fabulous deal, you won't lose out, and you'll encourage Washington wineries to keep doing what they do so very very well.