Microdol developer and Microdol Replenisher in 1qt sizes. These are unopened metal tins from ages ago. I have been using these, as well as the Mic-X variety of developers, for years w/o any problems, but both are sold as-is. They are both unopened, and sound perfectly fine when you shake them. Fantastic, low grain developer for most 100 speed films and slower, although I have used Mic-X w/ faster films w/ excellent results. Figure on losing one stop when used full strength.
The developer is good for about 8 rolls of 35mm film according to the can, but my experience is that you can get much more than that. The replenisher allows you to get at least 30 rolls from the 1 gt size developer. Good value for the money, and a great developer, period. US sale, and both the developer and replenisher are just $16 together, plus $7 priority mail shipping.