Thank you for your answers and support. I have tried to bid at Priceline for a few times but I didn't achieve. I have booked two hotels from hotwire for san diego and los angeles. Since the price is fixed and it is possible to read the user reviews at hotwire, it seemed more clear to use it to me. I will try to learn priceline bidding tips. My last question is; for a first time visitor what areas do you recommend at Manhattan? There are a lot of regions in there, which ones are more convenient for touristic areas?