1. You dont need to buy servers. You can resell them from other providers like Leaseweb, OVH, Softlayer. They will give you bigger discount with every new client. And then you be big company, you will start to do your own servers.

You will save time on managing server, money on bad hardware etc..

2. Make good website. Really good, current looks like crap.

3. You can use WHMCS for managing billing and servers, VPS, etc.. it will be enough in the beginning. Monthly license only cost 18$/month, and lifetime 350$