You bet!
It's a lot better (IMHO) to get a dirtbike and make it an occational trackday motard, than trying to get a dedicated motard street bike.
I HAD the street tard......and while it was sweet....it was a novelty at best. It ran it's course and I decided to sell it (like everyone with those DRZ400SM's do just as soon as they mod the piss out of em) after about a year and a half.
I now have a dirtbike that I can make a tard in 30 minutes or less
And it cost next to nothing when you consider the cost of a new(ish) sportbike.