Comparing apples with pears .. or cars with trucks ... or Rasbpery with PIC...
(Even PIC microcontroller have a huge variety .. with huge difference in features and processing power)
Technically they are so far apart ... a comparison makes no sense at all.
If you are just for selling numbers ... then I guess an internet search will do the job.
I am in fact looking for a relatively cheaper Raspberry pi or PIC Microcontroller with ethernet module integrated. I am not sure which one is more easier to work with.
Raspberry Pi has all the Ethernet hardware on the board, a PIC is just the processor, you still need the magnetics and power source and connector. Also Pi's run Linux OS, you have to write your own for PIC or use libraries in a development environment. Cost wise, the Pi is complete and ready to go, a PIC is cheaper for the MCU but when you add all the hardware costs and PCB there probably isn't much difference between them.
Are you really serious that you insist on asking this question for which there is no answer?
As I said before, these are both different hardware platforms intended for different purposes!
Furthermore, you did not provide any tips about the application in question.