Adorama - Canon Clearance Event + 10% off coupon: EF 70-200mm f/2.8L IS III USM - $1,620, RF 70-200mm f/2.8L IS USM - $2,430, Speedlite 600EX II-RT - $359 $1620
Adorama[adorama.com] has Canon Clearance with 10% off promo code CA5PH7CND (YMMV, see update)
UPDATE: The coupons are sent from Adorama in emails "Last Chance: your exclusive Canon lens coupon code expires soon!", so it looks like the coupon is personalized and most likely one time use. You can use mine - I don't need anything form this list. FIFO.
Thanks @etphonehome for catching this.
NO TAX for most states (YMMV), Free Shipping available for most items.
USA Warranty, of course.