Just like BlackIce stated, really depends on what you are after.
Decent rooms with a nice (not too cheasy) hot tub can be had for ~$140 just a bit off the strip.
Do a search for Niagara Falls hotels and you will find many have the rates for teh days yuo choose and usually have a good picture or virtual tour also.
Niagara Falls Howard Johnson = only hotel I have been woken up by the hotel manager after passing out in the hallway with a beer in one hand and a camcorder in the other. Good story actually.