One small, typical example: most of our VPN customers are setting up some satellite that needs to connect to the home office. The connection is initiated from our network to the home office. So the IP address of the satellite doesn't really matter.
This is not always the case, but it is the most common case.
So when a customer demands a dedicated static IP address, I wonder if they really need that. We charge extra for that because we have a limited pool of public IPv4 addresses. We can do it, but it is usually unnecessary, and better to avoid unless you really need it.
The connection is initiated from our network to the home office. So the IP address of the satellite doesn't really matter.
I'd assume they're restricting access further by only allowing certain ips thru a firewall in front of the VPN server, or requiring extra auth factors from unknown ips, or something.
It's not needed but troubleshooting is much easier for the sysadmin from the mothership and 3$/month for a static IP is literally nothing for a business.
We also always get a static IP for everything, because what do you do If the vpn doesnt come up after a firewall reboot ans the IP changed?
Network connections are much like everything else in life. There are lots of ways to do it. Which way is best depends on your needs. So to match up the most cost effective solution requires a knowledge of your requirements and a knowledge of the options.
When you have a corporate IT rep who is clueless about the options, they are not in a great position to build the optimal solution.
When you have an ISP rep who is clueless about the requirements, they are not in a great position to build the optimal solution.
When you have an ISP rep who is not willing to explain the options, you have a problem. When you have a corporate IT rep who doesn't know the requirements, is unwilling to explain the requirements, or is unwilling to learn about the options, you are unlikely to achieve the optimal solution.
When you have a helpful and capable ISP rep and a cooperative and capable IT rep, the world is a brighter place. But some levels of trust require either naivety or time and shared experiences. That's difficult when every contact between the customer and the ISP involve different people each time.
So, again, just like everything else, try to work with as small and local of an entity as possible to get the job done. This is true for government, auto dealers, ISPs, or anything else. Only scale up when there is an advantage to doing so.
This is not always the case, but it is the most common case.
So when a customer demands a dedicated static IP address, I wonder if they really need that. We charge extra for that because we have a limited pool of public IPv4 addresses. We can do it, but it is usually unnecessary, and better to avoid unless you really need it.