Never had white truffles, but I have had black truffles (on a pizza of all things). Black truffles don't really TASTE like anything, because the amount you put on a dish is so minuscule (a few shavings; it's more like a seasoning than an ingredient). However, they add a particular and unique fungus scent. Like you know that smell you get in your shoes after you sweat in them for a while? Take that and make it really "sharp" in smell rather than dank, and it's pretty much the same thing. From what I know, white truffles are just a stronger version of this. I don't get the appeal.
But here's the thing. Because truffles of both varieties are only added to a dish in the form of a few tiny shavings, the size of the thing is meaningless. They say "the bigger the truffle the more valuable it is" but that's nonsense. A diamond is more valuable the bigger it is because a single huge diamond can be sold for more than a dozen smaller diamonds of the same combined weight. But a single large truffle will never be served WHOLE, so it's only as valuable as the shavings that it will become. Therefore it must be worth exactly the same, gram per gram. In essence, it's a huge diamond in a world where the only use for every diamond is being ground into powder for industrial applications.
Oh, and if you want that particular truffle smell for your own food? Just by truffle oil. It's not made from real truffles (just oil and some chemicals cooked up in a lab) but is basically indistinguishable. It's the same thing as real vanilla versus artificial. Only idiots think there's a real difference.