Over at Amazon, these Irwin Quick Adjusting Wrenches (metric) are priced pretty low: $6 for the 6″, $8 for the 10″, and $10 for the 12″, which is less than half of their usual prices. The wrenches are sold by Tool King, and shipping is free. If you’re looking to put together a complete set, note that the 8″ is currently $14.
Although only the metric versions have been discounted, the entire line may have been discontinued. Irwin’s webpage for these wrenches appears to have vanished, with a 404 error page popping up instead.
Irwin Quick Adjusting Wrenches via Amazon
It is important to mention that, unlike ordinary adjustable wrenches, these wrenches have discrete stop positions corresponding to metric socket sizes. The wrench can only be set to metric sizings, and as such it cannot (should not) be used on SAE fasteners.