I have a listening room suspended over a two car garage and had quite a time getting vibrations under control. What I did was this:
1. Very heavy Timber Nation 4 Shelf Maple rack with spikes at every shelf support...
2. Iso-Pucks under all equipment.
3. 9 large 4" thick bass traps..two corner and 7 wall
The isolation table suggested above is a good suggestion. I would not buy a new turntable and cartridge unless you were going to spend a good bit more...and my suggestions above would cost many times what you want to spend on a turntable..so isolation table and Iso-Pucks where needed are the way to go, or relocate your listening space. Also, people use wall mounted turntables to overcome this sort of issue.
I hate to mention this, but for the best "bang for the buck" used digital is probably the way to go. I say this because I had to spend four times the amount on my analog gear to get it to sound better than my digital equipment.