Although the 110's didn't sell out previously, if you really want it don't take any chances. Add it to your basket the second it becomes available and you then have 15 minutes to go through the checkout process.
On both occasions where the 310xt were offered, they were all gone in a little over a minute.
Tenjiso
Thanks for the advice, without it I probably wouldn't have got it.
We were away visiting relatives this weekend and at a Christmas Fayre Satruday evening. I managed to sneak off just before 6 and logged on using the Amazon app on my iPhone. I added it to my basket as soon as it became available. After going through checkout I noted that all models had gone within the first 5 - 10 minutes.