By default you get IPv4 with CG-NAT and a static IPv6 /48 block for free.
Buddy support has stated that a static IP for IPv4 is available for $10/month $5/month.
From the Buddy Telco help centre.
Can I opt out of CGNAT or use a static IP?
Yes, you can get a Static IP! Add to your service through the Buddy Telco portal. All you need to do is log in to your account, select the "Static IP" bolton under "Advanced", and click "Apply Bolton". The cost will be charged in full on your next invoice.
Unfortunately, we cannot opt a service out of CGNAT without adding a static IP.
As you can see, they did not list the price here. So I asked, and decided to post it here to make it more available. Screenshot here: https://imgur.com/a/gq3nQw8

Also, I checked with AGL Internet as I wanted to sign up to the 6 month 250/23 for $74/month bundle (for 6 months then $99/month after).
The customer rep mentioned that static IP is available for $7.50 extra a month. I tried to ask about just opting out of CGNAT but they kept referring me to static IP.
If you want to cancel the bundle (i.e to not pay the $99/month after) the rep mentioned you can cancel on the same day and there is no cancellation fee.
I am considering moving to Leaptel for the 100/20 plan for $79 for 12 months. Currently on Exetel 50/18 for $75/month. Tempted to go for Buddy.