Trust me they won't be going stale...steady flow of 'customers' helps there. As an aiside, 15 years brewing and roasting has taught me that the phrase 'stale coffee' is far too widely used. What is stale anyway? How do you define stale coffee?
For me, bean change over a period of four weeks or so, sure the first week or two are the pinnacle, but to suggest (Not that you are) that beans over this period are stale, I have found is, well rather snobby.
They change, the chemical composition changes, the oxidisation changes the taste, sometimes for the better.
But be rest assured, they are not and will not sit there forever.
On a side note...I had cause to visit a farmers house yesterday and was offered a drink. I spotted a machine and grinder. They refused to make me a coffee because they felt the beans really were too old. (We are talking several weeks). I was impressed and promised to drop in some fresh roasted coffee for them!