VideoCardz leaks the suggested retail prices of the upcoming Radeon RX 570 and Radeon RX 580 video cards. This is the pricing for the standard versions and it includes 20% VAT. Models with overclocked frequencies and/or custom designs will probably be a bit more expensive.
AMD Radeon RX 500 Europe pricing:
AMD Radeon RX 580 8GB: 269 EUR
AMD Radeon RX 580 4GB: 239 EUR
AMD Radeon RX 570 4GB: 199 EUR
If the prices are an accurate reflection of the prices that will be charged by retailers, it looks like the Polaris refresh will not be cheaper than the Radeon RX 470/480 cards. In fact, the RX 580 prices are higher than what Radeon RX 480 cards are selling for today.