Maybe the large purchases are for a syndicate in some work place or a large family group. I used to run a large works syndicate so had to do the lottery run every Saturday. Then take the tickets to be checked through the till just in case I had missed a win.
I work in a supermarket and a few of my shifts are on the Lottery & Cigarette Kiosk - it's not uncommon to have customers that spend huge amounts of money on scratchcards.
Oh no! I was behind a woman buying 60 euros worth at a newsagent's in Lisbon last year and was shocked by that. In fact the till broke down in protest just as the transaction was finished and I had to go elsewhere for my travel card!
Nipped into the Coop near dd's the other day for a couple of things, went to pay at the post office/lottery/fags counter.
Man in front of me bought umpteen different lottery tickets and dozens of scratchcards. Nothing else. The total was just over £126. I was in semi-shock all the way back.