I find if point offers decline the best thing to do is skip Sainsburys for a couple of weeks and the come rolling back with several items for 200 points and many more for over 100. Last week I collected over 2000 points but as soon as it drops away, I'll drop them again though at the moment I'm about 2000 short for a ticket I want. I don't know whether it makes any difference but I don't transfer the points out until I have the right number for the ticket I want so I have a huge Nectar balance at the moment.