100 GBP right now is 158 USD and they sold it for 140 USD (not counting fees) and are paying for the shipping themselves. Depending on exactly what they ship it for (it would weigh probably about 1KG with a 1 GBP coin weighing 9.50g), they lost about 25% in face value on the auction.
1) The first two sentences are pointless. You didn't buy 50 new pence for 25 cents, either. You bought ~$10-$15 worth of coins for $12, one of which has an exchange value of 83-cents. Of course, no bank in the US will accept GB coins, so the exchange rate is pointless unless you're planning a trip to the UK. 2) Book prices (depending on the book) come from surveys filled out by dealers of "reported sales." Since they're surveying dealers, that means that they're citing full retail. Why? Well, because dealers won't report the sales of specific coins from their junk bins to the coin magazine. 3) While your experience (which is very limited, whether you admit it or not) is that you can't get UK coins for below face, others have other experience. For example, I buy Japan yen and Thai baht for below face regularly. I tell the seller the exchange rate, then I offer 10%-20% below that for coins (depending on the amount/denomination) and 3% below for notes. They sell to me because the local banks won't exchange coins, and charge a 5%+ service charge for exchange of notes.
Tim, you can see your name, and I believe part of your address through the paper you are using for a background. Might want to crop em a bit....