Ever wondered how much does IP addresses allocation really cost to your provider? Well, that is easy. If we talk about the RIPE IP address space (majority today) then they have published their fees for PI (Provider Independent) allocations for LIRs (Local Internet Registry) which is by coincidence your ISP is. Here it is:
all prices Euro2014201520162017
Annual fee per LIR1750 + 50 per PI assignment1600 + 50 per PI assignment1400 + 50 per PI assignment1400 + 50 per PI assignment
Taken from ftp://ftp.ripe.net/ripe/docs/ripe-666.pdf