Current commercial/pay-for-use rates for V4BL/FULL List:

Annual Fee = $(AQPD / 1k) 
Multiplied by the number of DNS IPs/servers factor as follows:
 1  IP  = 100%
 2+ IPs = (100% + 30% per each IP)

Rounded up to nearest $5. With a flat-rate minimum $50/year.

Annual Fee examples:
 AQPD   1 IP  2 IP  3 IP  4 IP
 ====   ====  ====  ====  ====
  50K = $ 50  $ 80  $ 95  $110
 100K = $100  $160  $190  $220
 150K = $150  $240  $285  $330
 200K = $200  $320  $380  $440

Notes:
AQPD = Aggregate Querries Per Day (sum of all QPDs).
QPD  = Querries Per Day (determined by averaging over 30 days).
Resulting AQPD may sometimes be considerably larger than actual 
 number of IPs querried, and/or emails processed.
 (Some DNS servers may be "noisier" than others.)