Where can I find a GTX 1660 or a GTX 1070 for at most 450$ in The US or on Websites?

Here is your answer!

GeForce GTX 1660 Ti and 1660 graphics cards let you play with stunning graphics and performance.

Hope this helps you!

In the benchmarks above, though, overall the GTX 1660 Ti is the winner. It's as fast or faster than the GTX 1070 in the majority of tests, plus this highly efficient card is often more compact, quieter and more power efficient too

Explanation:

answer; numerous occupation(s);