There was a discussion of ARIN at ISPCON where Kim H. explained the funding policy in great detail to the people present. In this case the $2500/yr is not for each /24 registered but an annual fee paid by the ISP to buy service from ARIN (for one year) for their overall address allocation. If your total allocation is > /24 and < /19 then you only pay $2500 for that year. If it it over that then you pay for whichever tier you fall into.
People who have /24 - /19 should get IP space from their upstream. It's a lot cheaper for an upstream to pay X,000$ and charge based on the smaller allocations (a big money-saver - turns out to be like $40/yr/"C"). -- jamie g.k. rishaw dal/efnet:gavroche IAGnet/CICNet/netILLINOIS 'whois JGR2' for PGP keyID/Fingerprint __ Network Operations/TSD DID:216.902.5455 FAX:216.623.3566 \/ 800.637.4IAGx5455 "This isn't a stop light. It's a stop sign." - Scully, X-Files