People have asked me my thoughts on IPv6 adoption, and I have to honestly say I'm pretty bearish on IPv6 being quickly adopted. I try to enable IPv6 on all my friends' routers, but even today, many routers, though they support 6 (notable exception being DD-WRT.. WTF), don't enable it by default, which means they don't enable the dual-stack configuration needed for transition. People then place these routers in a dusty area under their computers or behind their couches, where they sit, basically untouched, for 10+ years until they blow up and require replacement.
The people I've talked to that happen to control a lot of IPv4 addresses tell me that even at the current ~$10-12/ip strike price, nobody is interested in selling because the IPs are more valuable to them for use with datacenters and leasing than for selling them at auctions. And nobody's putting pressure on the people that own huge IPv4 subnets (and I genuinely doubt use all of it) to start splitting them up and releasing them. Not to name names, but the original developers of the Internet come to mind (huge research universities like MIT).
As such, I'm expecting the price of IPv4 addresses to increase substantially over the next 10 years, and I'm really not anticipating that price to drop for longer than that even. Because at the end of the day, if you want to support everybody, you need 4. And even today, dual stack is not the default option (despite ISPs like Comcast being ready for it). IMHO, If you need IPv4s for something like an Anycast network or a hosting service, the time to get them is now.
As for IPv6 transition, the best way to improve this problem is to do your part to get ready for it: https://blog.apnic.net/2016/05/04/you-have-ipv6-turn-it-on/