Mode S transponders can report altitude with 25 foot resolution. All transponders are not limited to reporting altitude in 100 ft increments.
Aircraft with less than 30 passenger seats are not required to have TCAS II installed.
Calling the FBO's and asking about fees will get you much more accurate information than you are getting here. There were three single engine aircraft on the Atlantic ramp yesterday afternoon and our fees for a mid size jet were less than the $350 you had 'heard'.
TEB is busy, but it is the...
Pick an instructor that has actually flown IFR in the system, not one who has never been on an IFR trip besides the dual given under the hood for the rating. The more experience he/she has, the better prepared you will be after the checkride.
There is a little bit of BS going on here. I have used Landmark multiple times and have never been 'turned away' approaching their ramp. It is just off the road to the terminal.
I have used all the FBO's at HPN except Signature and Panorama is the cheapest.
Instructor must have experience beyond going back and forth to the practice area and flying the same dual cross countries over and over and over again.
No 250 hour wonders.
Off airport, but less than 5 minutes from the terminal front door to ordering with JC. One stop sign and two red lights. Will have the food within the next three minutes.