They have the reference design Sapphire of RX 470 with 4GB, which are significantly cheaper, but they don't come with DVI-D, which my monitor has, its an older monitor, also its only got 6pins, so limited OC headroom.
The Nitro 470 8GB is more expensive than the 480 4GB and from what I've seen in most benches 480 4GB beats 470 8GB by about 10% if we take slightly manufacturer OC versions like the MSI's Twin Frozr for example. So far the extra 8GB seems to help the RX 480 over the 4GB a bit, due to the higher clocks by default.
So the question is will in the future ram bottle neck more than core? And again if the 470 8GB was cheaper, even slightly I would have probably mentioned it here and possibly went for it, but its about 15 euros more expensive.
470 4GB and 480 4GB are very similar in price here, about 10 euros difference, if it was like in the USA where you can find literally $170 470 4gb, with rebates even $160 or whatever, compared to $200, of course it makes more sense, but at about 10 euros difference, I'd rather go for the faster option.
They have a reference design one from Sapphire at about 20 euros cheaper, but it doesn't have DVI-D output, it also has 6pin only and since its blower style from the reference designs which from all reviews hovers at about 90C degrees, I'm not comfortable getting it and having it throttle due to temps, use hdmi to dvi-d converters and increasing input lag and maybe even possible issues with the converter cables, etc... So its not an option.