I actually bought a book brand-new, from a shop, and didn't go out intending to buy it. There are a few mitigating circumstances, m'lud. Firstly, I only went into W H Smiths because I had a voucher to buy this month's 'Delicious' magazine for £1.00 (saving £2.30 off the cover price), they didn't have it! Then, I honestly thought this book was only £2.99 if purchased with today's edition of The Times (it wasn't, as I discovered at the checkout). Finally, for £3.99 I thought it was well worth getting some ideas from.
It's an amusing little tome with some usual and not so usual ideas for making a bit of extra money. The usual suspects are car boot sales, selling on ebay. on-line surveys, mystery shopper (I've always fancied having a go at that myself), selling home-made craft items (I do try with that, with various levels of success), making jams and chutneys to sell etc etc. The not so usual ideas are being a porn star (I think not in my case), breastfeeding consultant (I can see this might be good for some people), surrogate mother (too old now, thank goodness), fishing and hunting (eww, no thanks, hate fish of any description and also hate meat in the 'raw').
Some of the ideas that quite appealed to me were foraging, taking in ironing (I knew someone who did this once and it was quite successful), proof reading (I used to be a 'scrutineer' on the local Bristol newspaper many moons ago), and treasure hunting (tramping round a muddy field with a metal detector has always held an odd fascination for me, although I've never done it.)
All in all, not a bad investment for £3.99, although I bet I could have found it in the local library if I'd not been so impulsive.
Edited to add: There is a website to go with the book.