Black Truffles are wonderful mushrooms to splurge on if you have the extra money.  Since JP loves them I try and get them whenever I can.  You can get good domestic ones which are far less expensive then the foreign but the domestic truffles usually don't have the strong smell or flavor that the european ones do, but again are a great alternative.  Some chef's infuse some of the truffles with oil's to make the scent and taste stronger.  I think if they aren't that strong in smell or flavor then they might not be worth the extra money but you will have to decide and take it on a case by case basis.  Normally you want to buy ones with really strong smell and firmness.   Whole foods and Central market will sometimes have these available in the summer and winter time.  There are endless recipes for truffles.  Simple ones are to just slice thin on pasta with butter or cream sauce or in scrambled eggs.  I made a black truffle and chestnut mousse that I stuffed inside a chicken and sous vide it.  I hope to bring more recipes for truffles in a few weeks.  I will be in L.A. for the next few weeks and the farmers market in Santa Monica, and in Malibu always has a mushroom guy who has truffles this time of year.   White ones are even stronger in smell and taste so I will try and get those if they have them.