The reason they can offer so much for so little is that there are a squillion users sharing the server.
The CS-Cart recommendation of siteground.com is the reason I almost didn’t buy CS-Cart.
Why CS-Cart recommend this web host is crazy, given that very few have anything nice to say about them.
My personal recommendation is cyberlnc.com
The guys there are very professional and helpful.
I assist CyberLNC with cs-cart related stuff within my skillset.
That said there’s no much I can normally assist with as the server takes care of the rest. All in all, siteground = ****. there will be others that defend it, but for that price you’re going to get ****ed around
CS-Cart went down for me all the time… They almost lost everything on my server twice before I lost and went to westhost