Just try the lite version first. If it is good enough, you can switch to a higher plan later. No need for adding 10 apps at once.
You will never be able to get the same results with your own server.
I was struggling with slow delivery myself. I tried different solutions.
I could send maybe a few thousand messages per hour. They can send 250 million(!) per hour based on their website.
PushWizard is a new site. I assume, they try to cut the prices under the others, so they can get a share.
Maybe they will go up later, but for now it is a bargain and I wanted to catch my package before it gets expensiver :-)
I know the company from other services, so I don't think, they will mess around.