New SLR...lense is everything?

I have been reading peoples recommendations on cameras and noticed the comments that "Lens is everything".
What I am curious of, is there a cheap SLR out there that has alot of the basic features, which I can buy a high end lense for, play with...then get addicted and once I am, buy a good camera and still utilize the lense?
If so...any recommendations?

Thanks
Jase