I know you introduced the setup fees to prevent the server turnover issue, and then more recently added the "loyalty price" for 6 and 12 months renewals, possibly for the same reason.
But then you added the Essential+ range and made everything pointless.
Let's take in consideration the SYS-32-2 and the SYS-IP-2. Both come with two 2 TB hard drives and 32 GB of RAM. The first one has a better CPU, but then again the latter's RAM is ECC.
Now let's say one of your customers is paying for a SYS-32-2 and 10 IPv4 addresses, and they have been doing so for a year so. Now they choose to renew the contract for another year. That makes:
50 € setup fee + (21 * 40 € server monthly cost for 2 years) + (24 * 10 * 2 € IPv4 cost for 2 years) = 1370 € (and 600 € for subsequent years)
Now let's do the same for the SYS-IP-2:
50 € setup fee + (21 * 40 € server monthly cost for 2 years) + (10 * 2 € IPv4 cost, one-time fee) = 910 € (and 360 € for subsequent years)
That's a 460 € difference. ~40%. In two years. At this point a mere 50 € setup fee (70 € if you include the cost of re-buying all the IPv4s) to switch servers is utterly influential. And of course that's not the end of it, since it continues growing: in three years it'll be ~43%; in five, ~46%; and so on until it finally settles around 50% on the long term. Should I graph it for you? Here:
Now, let's say this customer has been with you for less than a year but they intend to stay. Obviously the most convenient course of action for said customer (or for anyone in a similar situation, really) would be to switch to the SYS-IP-2. Heck, even a SYS-IP-4 would be more convenient at that point (1330 € for the first 2 years and 540 € for subsequent years), and that comes with 3 times the RAM and 2 CPUs!
Lastly, let's not forget that all these figures don't include taxes.
So was the fact that the setup fee was introduced to prevent turnover untrue, are you making old customers pay for the new customers' resources, do all your old customers only use one IPv4 address, or is there some mysterious hidden variable that no one but your marketing experts can see?