It seems as though $300/night is very reasonable (and not easy to find) for a Manhattan hotel right now. The cheapest route would indeed be to try Priceline, but they will only guarantee a room for 2 people/1 bed so your wife & friend may end up sharing. Good advice to bid only on 4* but I would also include Central Park South area. Recent reports of wins for multiple nights are >$200 for this time period.
Quickbook is easy to use and lists most hotel's website prices without requiring upfront payment like hotels.com or expedia. Travelzoo has some specials for NY but most don't start until mid-Nov.
Just to give you an idea, I made a "backup" reservation for $280/night in the summer for our trip in just over a week. I've never seen a better deal, although I'll continue to look until the day before we leave!
Good luck.