Pretty sure 1GB isn't going to work well for things like CryptoNight and probably BBR.

The wave of the future seems to be to use lots of memory to make things ASIC resistant.

I personally wouldn't buy 750 unless you get them for $90 or less with discount.  They just aren't as future proof, but that's just me.

Carlo

EDIT: PS above is a hunch but I've never tested this algos on a 750.