Didact walks into a bookstore...
Didact: "OK, I'm not going to spend more than thirty minutes in here, and I'm not spending more than $50 on three items, I know exactly what books I want to buy, and I know exactly where to- hey, look, they've finally put the League of Extraordinary Gentlemen into a compendium edition in trade paperback! And they've FINALLY got the new HALO novel in paperback! Whoa, an illustrated edition of Dante's Inferno selling at a discount!!! Hey, a large-print edition of The Lord of the Rings! My dad's going to love this! And there's a leather-bound classic print of the Aeneid! Mum's been wanting to replace the copy that her friend borrowed and never returned for thirty years!"
Three hours later:
Cashier: "So, that's 10 items for a total of $205.83 with tax. Cash or credit, sir?"
On the train back home: