I know the OP is wary of bidding sites, so I'm going to mention this for anyone else who's watching this thread. Priceline is problematic for 4 people when it comes to rooms in major central cities: DC, NYC, Boston, Chicago, London, etc.
In those cities, many of the hotels that participate in Priceline may be older ones, many of which have some rooms that will not sleep more than 2 people. As Priceline only guarantees double occupancy (sometimes in one double bed in older hotels), it requires a bid of two rooms in order to guarantee having enough bed space for a party of 4. Suburban hotels normally would not require that, because, as a rule, suburban hotels are newer and have 2 double beds as the default room type.