That's a GTX1050Ti, from the very low end of NVidia. The price seems very high, for little more you already get a GTX1060. If your sister agrees to get you the same amount of money, you could get a GTX1070 instead, which is way faster then two GTX1050Ti.
Just to give you a perspective:
GTX1050Ti: 768 cores
GTX1060 3GB: 1152 cores
GTX1060 6GB: 1280 cores
GTX1070: 1920 cores
GTX1070Ti: 2432 cores
GTX1080: 2560 cores
More cores=better performance
The GTX1060 has a good value, if you want to save money. Thing is: if you buy a complete system, than the GPU defines what performance you get for all your money. An cheap system with a fast GPU is always better than an expensive system with a crappy GPU.
And if you plan to put two GPUs in a system, you need the ones with a radial fan. Google it and you'll se what i mean.
Just to give you a perspective:
GTX1050Ti: 768 cores
GTX1060 3GB: 1152 cores
GTX1060 6GB: 1280 cores
GTX1070: 1920 cores
GTX1070Ti: 2432 cores
GTX1080: 2560 cores
More cores=better performance
The GTX1060 has a good value, if you want to save money. Thing is: if you buy a complete system, than the GPU defines what performance you get for all your money. An cheap system with a fast GPU is always better than an expensive system with a crappy GPU.
And if you plan to put two GPUs in a system, you need the ones with a radial fan. Google it and you'll se what i mean.