Sure... I'll sell you a $300 video... you can make that check out to... [/sarcasm]
Probably the best for less than $300 (considering bitcoin inflated prices on the R9 280X) is the GTX 760, though the 770's a worthy upgrade if you're willing to part with an extra $30 or so.
Well the GTX 770 is a tad over 300 its like 330-340
But its worth the upgrade, however if your budget is tight and u ONLY have 300 and u cant wait get the GTX 760, its still a good card, and its under about 180-220
Due to inflation some AMD cards are not logical to buy, which is most high end cards.
So GTX 760 or 770, whichever you can afford.
ASUS and EVGA are almost identical in performance. The EVGA has a higher clock speed but the ASUS has a better cooler, so you can OC it higher.