My father was incredulous at such a specific recommendation for a bit of scratching around in the dirt, and even more horrified by the price, which I think was 17s 6d. Probably only my first pair of Levis produced an equal reaction. The fact is that archaeologists are extremely precious about trowels - and fiercely protective of their own. You generally won't let anyone else use your trowel. The reason for this is that trowels change with use, each in an individual way according to the way its owner has used it.
New trowels are very unlovely things, all sharp and springy.
The point is dangerous and it sticks in you. Then they get moulded down to a nice asymmetrical rounded tablespoon-sized thing. Eventually they look like teaspoons. They're pretty useless at that stage but few archaeologists ever chuck the things away. There is actually an inverse snobbery about trowels - the more battered and misshapen they are, the better.