i bought a 2009 KAWASAKI LE650-A for 70 dollars and it looks like they can be replaced with dirt bike tires
Of course you can. I have been putting dual sport tires on street bikes for years. I know guys who put knobbies on their Sportsters. The Versys is a relatively light standard with a fair amount of suspension travel and decent ground clearance. It should work at least as well off-pavement as the Suzuki Vstroms, which people knob up all the time. Before the Versys hit the market, dual sport riders were hoping it would be a bit more offroad oriented. As it happened, it is pretty much a street bike, but is still light enough to do some exploratory riding on. With a pavement oriented DS tire like the pirelli MT90 or Avon Gripster, you can improve your bike's performance on gravel while giving up very little on the street. With a DOT knobby like the Continental TKC80 or Dunlop D606 you can really hook up on loose stuff and maintain decent road manners. Finding tires in the right sizes could be a problem, but the Cheng Shin 858 is a 50/50 tire that comes in a wide range of sizes. If you hunt around, I'm sure you can find something that will fit. Seventy bucks has to be a typo, right?
Dirt Bike With Street Tires