Paris in March/April, hotel recommendations?

hello:

im trying to plan a trip for me and my mother to paris in march or april 2009. the earlier the better with the way airline prices are going up.

i want to stay somewhere quiet in the center of the city...since im travelling with my mother, staying where all the 20 somethings my age hang out probably wont work out too well. looking for about $150 a night or less for 5-7 nights depending on affordability. im not concerned about small rooms, as that is the norm in europe, as long as ive got a shower in the room.

any recommendations would be awesome.

ps- the closer to the big attractions the better. eiffel tower, the louvre, champs elysee, notre dame cathedral....etc.