Which law schools? It's pretty easy to get around by the subway, but staying on the East Side if they're all on the West Side would be dumb. So, get a map, plot the schools, and work from there. Some friends of ours stayed at the Newton one time and it seemed to be fine, and is in that $100/night range (it's on Broadway in the mid 90s, IIRC (so it's the West Side)).
PM if you need more suggestions -- got married in the city a year and half ago, so I looked at a ton of places in your range.