In case you don't realize, companies that offer such plans as nemo is offering (with all due respect, I might be wrong, but my experience talks), are not going to buy new servers for each customer, even though their needs or actual plans may exceed the specs of the server... indeed, all they do is oversell their servers, hoping they'll generate enough eventually to buy a new one later on. I wouldn't term that as exactly reliable, and I think most of you would agree. Remember, even "pseudo-established" companies like NationHosts was run wasting people's money, which eventually caused a major chaos many months back.
In the meantime, within 5-6 mths, you'll probably come back here complaining about downtimes, or lost data, and/or hackers; hence, sometimes, if you're data and your company is important to you, sticking with guaranteed, reasonable and feasible priced hosting plans would outweigh the benefits than a huge, mega-giga server whose lifespan is not permanent.
On the other hand, not everyone is always concerned about the above, or don't think something will happen with their service they paid for. This rant does not apply to them in that case.
Just my 2c's... and I'm only talking in general about these "huge plans for cheap", not to anyone in particular.
Cheers,
PolurNET