You don't need those expensive fancy strobes / speedlights to light up a night shot. This shot happened as I was taking shots of the night sky, in the hope of catching a shooting star & a car drove by, lighting up castle Oliver in County Cork. I did get a shot of the shooting star - see here. The passing car lit up the castle perfectly. I'm sure the driver was wondering why the mad eejit was out in the pitch black looking up at the sky with a camera & a tripod.
This castle is only down the road from where we stayed for the week. I have to recommend the place as it's perfect for night / star photography due to the complete dark skies [no light pollution at all] & in the middle of a forest area, which was really impressive too. Have a look at their site here & tell John I sent you.