I had a bit of a dozy French teacher in my 5th year (don't know what they call that these days - final year anyway), nice bloke just not exactly alert.
The classroom we had our lesson in also doubled as the 5th year common room so had tea making stuff in it. We had this game where four of us took it in turns to do a lap of the room and move something on the way round, if you got caught you were out, last man standing was the winner.
On our best day we started off easily by gradually moving one of those roller blackboards on wheels from the front to the back of the room, but before the end of the lesson had got the kettle out the cupboard, filled it with water, moved it to the back of the room, plugged it in and got it boiling before being spotted.
Back to the Buffs I think your pre-order way would be good Sylv to get the best price, round it up a bit as there are bound to be some who see them and then decide they want one.