Here are those cards ranked in order.
1060 $210. 3GB, 1152 Cuda Cores, 8Gbps
1050 Ti $140. 4GB, 768 Cuda Cores, 7Gbps.
1050 $110. 2GB, 640 Cuda Cores, 7Gbps
750 Ti $140. 2GB, 640 Cuda Cores, 5.4Gbps
So with a 1050 Ti you get a decent amount more performance than with a 750 Ti, for the same price, even with a 1050 you get a little more performance for LESS than a 750 Ti.
The best thing would be a 1060 as the increase in performance is very significant and more than makes up for the cost.