Cheap Supermotard

Ok so im getting my bike license next month along with two of my other friends. None of us have any real ridding experience. One of my friends just went out and bought a 08 GSXR-600 which i think was dumb because hes going to dump it lol I want a Triumph Daytona 675 but I decided im going to get a dirt bike instead and a street bike next year. Hears the plan I want a supermotard so I can ride it on the street and learn how to carve up the back roads but also still take it off road. I also want to ride it around town. So who makes the best supermotards for the price? I love the Aprilia's and KTM's but their probably too expensive. The other thing I was thinking is what if I just bought a dirt bike and put street tires on it? What type of dirt bikes would be best for that?