I would say choose if you want a budget card right now (rx480) or if you want a more expensive, more powerful card, wait for the 500. You probably already have a new one, but just helping :)
RX x80 are not "budget cards" the "budget" for AMD ix x50/x60 for Nvidia it tends to be similar x50/x60 naming e.g RX 460/550-560 or 1050/1050Ti.
480/580 or 1070/1080 are "performance" level, not budget, can tell by the price anything $250+ is not a "budget card" the budget ones are usually $180 or less.
Cannot tell via the amount of memory used, can only go by the product number designation numbers.