Asus RT-AC66U Dual-Band Wireless AC1750 Gigabit Router + Windows 8 Pro Upgrade $149.99 AR @ Newegg
If I am not mistaken, this is the lowest price for this router or this bundle. If you have an actual need for the Windows upgrade (or sell it on CL/eBay), it is a very hot deal.
$189.99 - ASUS RT-AC66U Dual-Band Wireless-AC1750 Gigabit Router IEEE 802.11ac, IEEE 802.11a/b/g/n, IEEE 802.3/3u/3ab [newegg.com]
FREE - Microsoft Windows 8 Professional Upgrade [newegg.com]
$189.99 - $40 Windows Rebate [newegg.com]
= $149.99 + Free Shipping
I actually chatted with Newegg's customer service and they confirmed that this will qualify for the rebate.
- There is an Open Box [newegg.com]
available on Newegg now for $133, if you are quick enough. There are at least 5 in stock right now.