IPv6 is important, but it's not like your ISP will lower your bill if you forego IPv4, and it's not like there are IPv6-only sites. If I recall correctly, I have to pay _extra_ for an IPv6 address.
IPv4 addresses have been more expensive than IPv6 subnets on every dedicated uplink I've gotten prices for over the last two years. In fact, an IPv6 /56 is usually free, or cheap enough to be effectively free since the fee is mainly a NRC for the time to set up the route, if you ask for it and the provider supports IPv6. In contrast, IPv4 addresses often incur a MRC based on the number of usable addresses you request.
> If I recall correctly, I have to pay _extra_ for an IPv6 address.
That's weird, here we get a /48 v6 block by default and one /32 v4 address. You'll never need more v6 addresses, but each v4 address comes at a monthly fee.