Amazon offers the Amazon Echo Voice-Controlled Bluetooth Speaker in Black or White for $179.99. Add two to cart for $359.98 and apply coupon code "ECHO2PACK" to drop that to $279.98. With free shipping, that's $139.99 per unit and the the lowest price we could find for this quantity by $78 (outside of the seller below). For further comparison, we saw single units for $150 each last week.
Don't want two? Overstock.com offers it in White for $156.39 with free shipping. That's a low for a single unit by $23.