First of all, I would recommend using Priceline.com’s “Name Your Own Price” option for Paris. We have never gone wrong with this. I have checked the map and I feel that everything in the city is probably a fine choice. Don’t pick the area a little further out from the city. You will take too much time travelling that way. With Paris, I would start at 70 dollars per night in the hopes that you might get lucky and slowly work your way up to 100. If you are there in a low season, you might be surprised at what you can get. The catch with Priceline is that your card is automatically charged and you can’t change your reservation. We have used Priceline 3 or 4 times and have never had any problems. Also, when you are trying “Name Your Price,” you only get one try per credit card every 24 hours. Our trick was to use more than one credit card.
If you are looking at areas to stay in Paris, I would suggest the Latin Quarter or Montmarte. There are many nice areas, but I happen to enjoy these two.
Again, I really recommend Priceline, but if you insist on staying somewhere extremely cheap (I still think you can get a similar price for something nice on Priceline) then the Hotel de Nevers is quite charming. It’s located near Republique which seems to be a fine area. It’s about 2 blocks from a Metro station. The staff is incredibly helpful and there are a number of cats living in the hotel. The hotel is not fancy at all and you really should try to request a room WITH a bathroom. The walls are paper thin, just a warning.