For your primary servers, power is a very important cost consideration of course.
On the other hand, I buy Raritan 16 port IP KVMs that are BETTER than their new models at 90% lower cost. I use them a few times power year. Their better than the new ones because they have a perfectly good web interface I can use from my phone to take care of a server that it down, rather than having to drive to office to use their proprietary control software for the new ones.
Similarly, I use some very popular 16-bay storage boxes that I get for around $100 used. It's nothing more than a metal box with a SAS expander in it. There's darn little that can go wrong with what is essentially just a case and sleds, so why would I want to pay $X000 each for them?
The people talking about tax depreciation obviously haven't thought it through. You pay lower taxes by having lower profits. Sure, spending $20,000 on equipment means you can (slowly) deduct $20,000 from your taxable profit, thereby reducing your tax by $4,000. You just spent $20,000 to "save" $4,000. That's not exactly a brilliant move, especially since that $4,000 is depreciated over at least five years. You want to spend $20,000 now to get $4,000 back five years from now? I see why you're a computer geek and not an accountant (or manager).