More specifically, in this context I think that the tendency to assume that market mechanisms would infallibly convert the fact/existence/ supply of additional loose (de-assignable, transferable, etc.) IPv4 into the enduring condition of greater openness to aspiring new entrants is based on the widespread (mis)perception of individual IPv4 addresses and prefixes as "things" (assets, commodities, etc.), when in fact they actually represent something more like discrete instances of a "generalized privilege" or "license" (as in "creative license" even more than "driver's license").
The minimum ARIN allocation to a new ISP is currently a /20. Someone recently offered an American ISP 6 figures for a /20 block that was acquired as part of a corporate acquisition. The ISP declined the offer and returned the block to ARIN. This could mean that the value of a /20 on the open market is 100,000 USD. Since a /20 has 16 /24 equivalents in it, that would place the value of a /24 at 6250 USD. According to <https://www.arin.net/knowledge/statistics/> in the first 6 months of 2009, ARIN issued 99,285 /24 equivalents to ISPs. That means that ARIN issued 620,531,250 USD worth of IP addresses. Over the course of 2009 we can expect some 1.2 billion dollars worth of IPv4 addresses to be allocated to ISPs, or $103 million per month. Where is the industry going to find 1.2 billion dollars to sustain growth of the network after IPv4 runout? And where is a new entrant going to find $100,000 to buy their first allocation, assuming that the price doesn't rise even higher when the free alternative no longer exists? Will the prices in Europe be any different than in America? Why? --Michael Dillon P.S. note that there are more predictable costs to an ISP in deploying either carrier-grade NAT or transitioning to IPv6. How will this impact IP address block prices and why?