Atm i had see this: 100cps = 1-1.2B 100cps = 100rp 100rp = 1B * thats an aprox ratio for me. There are exceptions like Mount Pill (15rp) selling at 300-350m in proxy shop
I sell RP base on penny = 1b... So for each RP= 1b... and you can see the price. for example a PC = 420 RP = 420b You can also give them discount like 50% or 90% off depending on how much demand there are for RP.