It's hard to tell what you are asking for. *All PnS cameras are compromises for cost and size reasons compared to DSLr
The best high ISO compact PnS is the Sony RX-100 with its large 1" sensor (marketing term but it is the same size as the Nikon 1) and fast Zeiss glass that starts at f/1.8. But at $650 it's a bit above your price range.
For me, I went with a travel zoom category camera. *Still mostly pocketable with a tremendous zoom.
I have the Sony HX-30 (same camera as HX-20 + WiFi) and have had a lot of fun with it. It has a 20x optical zoom with a 35mm equivalent 25-500mm (or like a crop body DSLr with 12.5-250mm) an amazing 1080p 60fps HD video with great 3-way optical stabilization that will probably beat your DSLr, especially when comparing hand held results.
*If your DH is looking for a camera to leave on Auto and have really nice pictures straight from the camera with out post processing, (and enough manual controls to have more fun with) then I think Sony is a great choice.
Here's a few pics from mine:
I entered MK, walked up to the hub, there was a castle show going on with a decent crowd already watching, so I kept on walking towards Tomowwowland, then I saw Mickey and Minnie on stage. *With the camera on Auto, I turned the camera on, zoom, click, saw the result on the screen and realized I love this camera because I didn't have to wait to get a great spot in the crowd, or lug around a tripod..
And I loved having the zoom on the Safari:
For low light:
ISAW:
FOTL:
The Boardwalk:
And A great in-camera Panoramic*feature:
And in-camera HDR:
And Wishes, from the Boardwalk *over the Yacht Club ( yes I really needed a tripod not a railing for this 2 sec exposure, but still it's an impressive reach)
I also believe that there is no one best camera for everyone. *Prior to the RX-100 the Cannon s95/s100 was the king of pocketable low light cameras and is still in your range. *And Panasonic just announced a few new cameras with fast glass that look appealing, so keep looking around, go to a store to feel them in your hands, and keep asking questions.