Consumer Reports tracks the prices on thousands of products all year, and just posted a list of the best things to buy in June. They include ...
1. Sunblock. Make sure the stuff you've got hasn't expired, and stock up for summer if you need to. It usually lasts about three years, and then it doesn't work as well.
2. Wireless speakers. They're cheaper than normal right now, including the outdoor kind. So look into it if you're planning any parties this summer.
3. Weed eaters. Which is good if you're fixing up your yard. You probably don't need a heavy-duty one. But the low AND high-end models should be on sale right now.