Ever.
No, seriously, it's not a single donation drive to get an amount of money for a once off purchase, if we don't get enough through sales then each year we would go cap in hand to the community for the next year of lease.
Of course, if we can get a bank up with a few years worth of funds this year, then future years become easier.
In terms of the initial drive, we're probably looking for about $3.5K or so, so keep that money flowing in peeps.