No, currently we don’t offer lower plans, and below there is an explanation why.
Actually even if an ARK server has no active players (or just 1 or 2 players), anyway it consumes really lots of RAM (4Gb-12Gb, 6Gb on average).
Since we don't restrict RAM in any way and since we don't use disk swap (it decreases performance) to limit RAM allocated to each user, we have quite high costs for each server's resources.
We suppose that some other providers could use hard drives and virtual memory (swap partitions). It allows them to make price lower however it affects performance of all game servers hosted on particular machine.
That is why we offer 50 slots plan as the lowest plan. However if you want to limit number of players you can do it in server settings.