Buy or no? It is a 24/7 onsite, no mention of response time so far.
A day or two down will not cripple or kill our business.
Server is only $1800 (plus three disks which are a separate $830 but not sure if they are covered).
I truly think if either hardware of software fails, I will use my tech support to diagnose and fix (I have a call in to them to see if they can do this). Do servers have an expensive achilles heel component in them which is prone to failure?
It depends on the quality of the hardware and how the server is used and maintained. Good-quality servers that are properly maintained and protected, and that are not used as workstations, are usually pretty trouble-free. Bearing in mind that I've been out of that end of the business for a while, I'll offer up some more observations.
I always researched all the parts of a server before committing to purchase it. I wanted to know the exact makes and models of all the components. They all have reliability histories that can be uncovered with some research.
As for processors, server-grade Intel and AMD processors tended to be pretty reliable across the board, but I wanted to make sure the specific processor was up to the intended job and well-cooled. Also, I had fewer problems overall with Intel than AMD processors, but I only had a handful of problems with either over the years.
Motherboards, on the other hand, vary greatly in their reliability. When possible, I always felt more comfortable with a year-old motherboard model that had an impeccable reputation than a brand-new one with no track record. All else being equal, I also preferred Intel boards for Intel processors, mainly because they were rock-solid stable and I never had a problem with one. I also found Gigabyte and Asus boards built on Intel chipsets to be very reliable and stable overall.
I also insisted on good cooling of the processor, chipset, and case. If there was no chipset cooler, I would often install one. I also tended to go a bit overboard on case cooling, and part of my routine service calls was cleaning the schmutz out of the machines (especially in dusty environments) using a static-free vac, compressed air, and brushes if needed. Don't underestimate the problems that schmutz can cause.
By the way, cleaning a computer is not as easy as one might think. It's probably best left to a computer tech. Any air blowing over components could cause ESD, and rapid cooling caused by compressed air used to dislodge stubborn gunk can damage components. It's a more delicate procedure than it appears and requires discretion and ESD protection. I did the job with the machines powered down and cooled to room temperature, which usually meant graveyard shift calls.
RAID controllers, whether on-board or add-on, are a particularly finicky class of components. They accounted for the majority of data-loss incidents on RAID arrays because they tend to corrupt the whole array when they fail. That's one reason why a good backup that is not part of the array nor controlled by the same controller is essential. In the old days we used tape drives. Nowadays, imaging to an external hard drive or online backup are more common solutions.
Hard drives, of course, also should be of high quality with good reputations. I tended to avoid bleeding-edge drives that pushed the envelope on capacity. As with motherboards, I liked some good history and preferred a slightly-older drive with a solid reputation for reliability over a bleeding-edge drive with no track record. If it was to be part of a RAID array, I purchased a few identical spares, as well. I also liked drives with generous cache buffers. This was both for performance reasons and because the cache reduced wear and tear on the hard drive. (This is also important on SSDs, by the way. Even though there's no disk, they still have limited writes.)
As for the warranty itself, it's one of those things. If you use it once, it will most likely pay for itself. Twice, and it's a virtual certainty. So it's a gamble, just like any other service plan. The most important thing is the reputation of the company issuing the warranty. If they suck, so does the warranty.
If you're happy with your local tech support company and they've been in business long enough for you to believe that they'll still be around three years from now, you may want to approach them about whether they'll issue a warranty on the machine. When I was in the business, sometimes I would and sometimes I wouldn't. It depended on the quality of the machine, whether my company would be routinely maintaining it, and my overall experience with the client.
Most of the times when I issued a warranty, I made money. A few times I got burned. It's a gamble for the provider, as well; and how well the provider will respond to a call they're losing money on depends on the provider's business practices and their ability to easily absorb a loss. If your local tech support company is hanging on by a thread financially, that could be a problem if an expensive failure occurs.
Rich