Frankly, a GTX 770 doesn't even apply in this situation and I'm unsure why you are mentioning a $400 graphics card when the OP is asking about $100 dollar cards.
Between the two of those cards, since essentially they both have the same "Cape Verde" graphics chip on them, I would pick the card with either the higher memory, or the card with the lower price. Decide which matters most to you, as you can easily overclock the 2 GB card yourself to the speed of the factory overclocked card. It isn't as though XFX is receiving special shipment of chips that have been speed binned for them, and likely, they are only upping the clock by a conservative amount.