No, tungsten is not quite that expensive! Machining it might be if you don't already have the necessary tools and equipment. Maybe you're thinking of that notoriously difficult to procure metal known a Unobtainium?
Originally Posted by http://stockcarsteel.com/tungsten/
Tungsten
Product Description:
The Tungsten that we offer is used primarily in the NASCAR Racing Series. Our Tungsten is offered in block form and is used as ballast in the Frame Rails of Race Cars. In confined spaces where mass is required for balance, tungsten-based high density metals are often specified. Race cars can be given just the right "feel" or balance to maximize performance. Our Tungsten-based chassis weights are more than twice the density of steel and 50% heavier than lead. Tungsten based Race Car Ballast can be used to lower the center of gravity and/or be used to adjust the balance between the front and the rear. Our Tungsten based ballast block is machined to move easily into a NASCAR Frame Rail with threaded holes on both ends for easy movement and attachment to the Frame Rail. The Standard Block is 2-5/8" x 3-5/8" x 6" and weighs 35 lbs. Stock Car Steel & Aluminum is the leading supplier of Tungsten Block to the NASCAR Racing Series.
Tungsten Block: 2-5/8" x 3-5/8" x 6"
$1,876.88
/ pc