gtx 970 sli vs gtx 780 ti sli?

It depends heavily on where the OP is based, some parts of the world simply do not do discounts on expensive hardware like GPU, if they do, they probably are clearing out several years old stock.

In US they probably will do discounts, where I am, they are still selling 700 series at MSRP.

Lastly, might take a while for 780 ti to fall to the level of 970's, if they fall. A quick scan through amazon and newegg does not suggest they are falling in price anytime soon.
 
I highly recommend the gtx 970 99% of the time its going to be cheaper than the 780 ti, but what could i say microcenter is awesome. I would say the 970 is a very slight stepdown from the 780 ti but taking a price/performance perspective into account the 970 performs on par if not better than the 780ti , its also marginally newer, overclocks way better than the 780ti, it has higher clocks speeds right out the box, and you have an extra gb of vram. On efficiency however dont be fooled when its underload it could spike to 300W. That being said, the 970 is a much better deal, i'd go with that.