I am not sure if your needs match mine, but I run Moodle with around 75-100 students each semester in it.
I have a VPS with GoDaddy, their "Value" plan, which provides 2GB RAM and 60GB storage, plenty for me to run Moodle. This cost (with cPanel, privacy, etc.) around $50-$55 per month.
I have had my VPS for around 3 years, and am satisfied.
You should recognize a couple things:
1) There are many alternative companies. GoDaddy is one of many. I think that you will find many pros and cons of GoDaddy posts here on moodle.org, probably because GoDaddy is one of the largest hosting companies.
2) Do you have the knowledge to run both a VPS and Moodle? Are you going to do it yourself, or have someone with the "knowledge" do it for you?
3) If you instead choose a "hosted" server (much less expensive) , be careful. Some of these do not have enough power, or proper software to run the latest versions of Moodle. For example, a hosted server with GoDaddy can only run Moodle 1.9x right now.
4) A hosted server is not a bad way to get started learning Moodle. These typically cost around $5 (more or less) per month. Once you know a little more about what you are doing, you can progress to a VPS.
In my opinion, based upon the little information that you have provided, is that you should consider VPSs based upon the spec provided by GoDaddy's Value VPS. Don't short yourself on RAM.