I don't put any stock in listing prices, because half of them are based off Youtube instructions on how to flip new registrations for $2,000.
Expertz.com is going to leak traffic to experts.com (not to mention be extremely clunky as a brand) which means that you could confidently drop 3 zeroes off the value of expertz.com, then drop another 2 zeroes for the .net.
I'd place experts.com at around seven figures, expertz.com at four figures, and expertz.net at two figures.
I wouldn't register expertz.net, as the price probably wouldn't cover the renewal fees.