VIP seats are real hard to sell. My top attendance was 9 (one less than 10)
It would be easier if you decrease the price and if you are in the top division. Last season I had 21/25 VIP seats through out the season with 22/25 at the relegation playoffs. But this season the numbers are lower because I am in a lower division.
I don't think the price is really the problem. You simply can't sell very many luxury boxes.
As absurd as it might sound, a new club that adds 5 luxury boxes (they start with zero) may be overbuilding.