I know what you mean, some of the cards on my want list are cards no one seems to have. I try to remind myself to just browse before finishing setting up trade offers because occationally you find obscure cards that people have up for trade and I love those types of cards.
I was considering starting a discussion thread the opposite of this one, in which people can show links of unusual cards they have up for trade that people normally wouldn't have on their want lists. Somewhere on this site is someone who would want that bizzar card but just don't know about it to put it on their want lists.