Hi ferry
for price check www.digi-key.com
for assembly 8051 is much easier because PIC is a RISC, while 8051 is a CISC.
I've been working with pics for a long time but I found that 8051 is easier to deal with.
however pic needs less components becuause it has built in POR circuit and each port pin can drive/sink 20/25 MA current.
Development tools for 8051 are much more mature - if you can afford them that is-
For hobbiests I recommend the pic because you get free develepment tools like assembler and hi-tech C compiler (completely free for 16F84) and free simulator.
Regards
Mahmood