Using a hosting service is much more efficient than using your own VPS.
Let's say that someday, your Blockland server got popular and had a lot of players on it all of a sudden, and the OS plus other applications use 512 MB. And Blockland uses 600 MB.
Now you need a 1.15 GB VPS just to make sure the system will never run out of RAM. The cheapest provider I know which is reliable will charge $8/month for this (We love servers).
By hosting yourself, you need 600 MB of RAM to provide "cushioning" in case the server may get popular.
However, let's consider a hosting service with 8 GB of free RAM (1.5 GB is uses by the OS and other programs). Since they can host more BL servers, the cost of hardware per BL serv. is cheaper. So now your needed RAM per server goes down to 275-350 MB per server instead of 600. The result? Since there is 6.5 GB of free RAM, you can run 20 Blockland.exe's. For this kind of system, it will cost $45/month (from Server4you). That means your average price per Blockland server is now $2.25 instead of $8.00!