First, Oculus Rift appeared in small numbers at Amazon and Best Buy but was quickly snapped up. Now the HTC Vive appears at retail. Micro Center first had ten available in their California store in Orange County. As of Sunday, only one remains, and you'll need to stop by in person to pick one up. The Vive at Micro Center is bundled with features such as Google Tilt Brush, Fantastic Contraption, and Job Simulator.
Microsoft store shows their supply as coming soon. Both stores have demos available if you wish to try before you buy.
The Vive retails for $799 which is the same as the price direct from HTC. Current HTC Vive orders are targeted for June shipping.