The store linked to above uses CafePress default prices (medium). You can instead choose what you wish to donate (added to the base price charged by CafePress), with one of these links - $1, $2, $5, or $10.

This nice design was contributed by David Sibley, who has also created a set of Mini vMac icons for OS X. 1986 is the year the Macintosh Plus, which Mini vMac emulates by default, was first sold. Macintosh software written from 1986 up to the mid 90's will usually run on a Macintosh Plus, and so can run in Mini vMac forever, so long as Mini vMac is maintained.

1984, the year the original Macintosh was first sold, is not used in the design partly because of the strong association with Orwell's novel, and in the end mostly because 1986 looks nicer in the design. The design attempts to avoid abusing Apple's trademarks, which is why there is no picture of a Macintosh on it, or even the word Macintosh. Apple's trademark guidelines can be interpreted as saying that "Mini vMac" is ok as a product name.

Buying from CafePress is one of a number of ways to help Mini vMac.