It is much you want from one source,
I think you need different sources,
What prices do you want,
Engineering, equipm., piping, instr., struct. electr.?
What plant? Ethylene, food, crackers?
Maybe there are sources for complete plants,
but presumable you won´t find it on the internet.
Manufacturers often put their prices not on the internet,
they make you an offer.
succes