Store avocados for say a month
If you buy them hard, and put them in the refrigerator right away, you can probably get a month out of them. After having been refrigerated, they will take longer to ripen at room temperature. So check them two days before you want to use them. If they're still a bit hard, leave them in a paper bag on the counter for twice as long as you would unrefrigerated avocados of the same hardness.