Currently a GTX1050Ti costs 54% the cost of a GTX1060 6G card, it mines at 59% the hashrate of a 1060 and uses 72% of the power of a 1060.
So in terms of cost it is slightly better but not really power usage
Seeing that it takes up an additional slot of a MB requiring more MB,CPU,RAM for another rig it probably isn't worth it.
Also have to take Resell value into account if you ever want to sell them. 1060 or 1070 will sell better later to Gamers than a GTX1050Ti imo.
Unlike the 1060's I can actually find the 1050ti's for sale.
And the price differential has shifted too - if you can get a 1060, they're expensive. The 1050ti is about 40-45% of the cost (not counting the crazy expensive ones people are trying to sell themselves on Amazon):