For a cheap headset, you're better off buying something used off ebay. Seems to be plenty of David Clark, Peltor or Sennheiser headsets on there most of the time. Though I bought a new Sennheiser HME-95 as my first headset. The benefit is that it folds flat and will go in a courier bag/ homo-satchel.
I'd also get an A4 flightboard (with plotter/ protractor/ pen pockets) instead of the A5 ones. I use one side for a plog and the other for plain paper to write down clearances etc.
Don't waste money on a stop watch. The examiner is going to ask you what your ETA is rather than how many minutes are left subtracting from the stop watch. So a regular watch is fine.
Don't buy a chart until you absolutely need it because it will go out of date.
You may want to get a plotter for easier diversion planning, since they will fit in the flight board and do two jobs at once (heading and distance).
Good luck with your training.