A lot of Google Maps "satellite" imagery is actually aerial imagery, not satellite. Getting that kind of detail and resolution with satellite photos is extremely hard / expensive.

If you want up to date imagery, you could certainly choose to task an airplane yourself, but that is going to cost a lot more than what SkyFi is charging for one-off satellite images.

So, no, the free preview is not better than the paid thing, and the reason they're using Google Maps is clearly to help you precisely mark the area that you want them to capture.