We will buy the majority of your truffles if you cannot sell them to other mushroom brokers or restaurants. This is not a problem, as the demand far exceeds the supply.
There are about 150 currently in the USA. Historically, the demand has always been higher than the supply, and is expected to remain so for the next 50 years.
Oregon truffles are a different species with less flavor. They are generally considered inferior and are not purchased by the Europeans.
Because most of the truffles come from Europe, the price is determined by their production. The lowest it has been since 1992 is $350, the highest $2000 per pound.
There is no guarantee that the trees will produce truffles, because this is largely determined by how you care for the trees as well as mother nature. Note: no effort, no truffles.
There are more and more people growing truffles every year. However the demand far exceeds the supply. Also, they only grow in certain climates.