should I buy a gpu with no pc yet

So I have been using a laptop for a long time but I am finally on atime in my life where I can save a bit of money and build myself a PC for a GPU I was thinking the arcB580 BCS price to performance is awesome and its right on my price range (is either that or go amd) the thing is I know stock of the new arc is very limited but a retailer here in chile has a few in stock for a very good price (about 280 dollars) should I buy that GPU before it starts to go up in price or should I wait to save the rest of the money for the complete build.
thanks in advance