At the current retail price, a half pound of beef is just shy of $5.
That price depends a lot on where you live and shop.
At my local grocery store (Fred Meyer, a chain owned by Kroger), ground beef is as little as $5.33/lb. It only gets to $10/lb if you insist on buying the 93% lean, grass fed, organic beef.
If I get it at Costco, it's even cheaper.