Is this a good PC for the price?

Solution
They don't tell you the exact model/series of the PSU. That already means zero trust on it being able to deliver safe operation for a GTX1070.

FD2Raptor

Admirable
550W doesn't say what model/series. They could be using the VS series for all we know (and where I am in South East Asia, the VS series is known as graphic card killer, only suitable for lower end system; but I wouldn't put it past these prebuilt guys to put it into the system to generate extra warranty expense down the line).