To be honest with you I'm not an expert on graphics cards, but I think it would be better to just get the galaxy gtx 770 if you want to save some money. The Asus is more expensive because it has a tiny bit more enhanced performance than Galaxy's version. In conclusion I recommend getting the Galaxy gtx 770 because its not worth paying 10$ for that much of a tiny performance increase when you could be using it on other things such as actual games.
Asus version has:
~Boost in performance, can be overclocked higher.
~Heatpipe design makes it much cooler. (As in less temperature)
~Much quieter fan
~Because of it's previous specs, it can last twice as longer in comparison even when overclocked.
Personally I'd go for Asus version because I can push further and it can last longer. Been playing a few games with it now with ultra settings, I don't hear any sound made by it, it's just so quiet.