Fair enough. =] I just don't feel that saying "They do it, so you can do it too" is a great way to ideal protection of a horse. Every horse slips, has an off day, etc, so why not protect them thoroughly? =]
As for where to get woof boots- the best place to look would be at a local tack shop. That way, no shipping costs are involved. Some people sell them on here, too, cheaper than you could get them new, so I'd keep an eye on that. Otherwise, Woof All-Purpose Boots - Dover Saddlery.
They're on sale for $29.90; only a little more expensive than what I paid at my local tack store.