The list of precursors in Europe is regulated by the International Narcotics Control Board.
Phenylnitropropene (P2NP) is not on their lists, but in their reports this substance is highlighted as a precursor of amphetamine.
There is another problem, p2np has no legal purposes of use, so it is difficult to justify it.
Direct purchase of this substance is not prohibited by law, but you can easily get into the field of view of law enforcement agencies.
In Europe, prices are quite low in the range of 200-300 euros per 1 kg, in my opinion it is very cheap.
In those countries where p2np is prohibited or in cases where you do not want get burned when buying of this substance or to reduce the cost, you can synthesize yourself.
The production of this substance is very simple, the synthesis is easily scaled, does not take much time and does not require expensive and complex equipment.