SAVE $35: The Kindle Paperwhite Signature Edition (32GB) is on sale for $164.99 at Amazon, down from the standard price of $199.99. That's an 18% discount and it comes with three months of free access to Kindle Unlimited. $164.99 at Amazon $199.99 Save $35 We're in a mellow time in terms of sales. The next major event will happen over Memorial Day weekend and the next big Amazon sale is Prime Day in either June or July. It's not often we see discount on Amazon's own devices outside of major sale times, but we're all in for a little treat today. As of April 27, the Kindle Paperwhite Signature Edition (32GB) is on sale for $164.99 at Amazon, marked down from the list price of $199.99. That's an 18% discount that shaves $35 off the normal price. Over the years, Amazon has expanded its lineup of Kindle e-readers , but the Kindle Paperwhite Signature Edition remains Mashable's favorite for those who read often. It comes with a handful of upgrades that frequent readers will find well worth the added price.…