A lot of people seem to think so. I can recall a conversation with a coworker where I mentioned I was going to pay off my mortgage. His response was that I would lose the tax deduction. My response to that was I would be happy for him to give me a dollar and in return I would give him a quarter. Furthermore I said I would do that for as many dollars as he would be willing to do that with.
Tax deductions are nice for things you're going to buy anyway but they shouldn't be the reason for a purchase.
That was my point exactly - in my experience a LOT of people seem to think that "it's a tax write-off" means it's free.
Okay, it reduces the effective price - which then people bring up the other completely illogical point, "you have to buy it anyway." But unless your alternative is to buy a computer that does NOT benefit from the tax write-off (really just a reduction in profit tax), the point is silly - they're comparing different things. If one computer costs $1000 and the other $1500 and your tax rate is x%, the pricing differential is basically still the same.
(And for anyone who doesn't get that - try this argument the next time you want a raise, just tell your boss they should give you an extra million dollars because "it's just a tax write-off anyway.")
And there are also a LOT of businesses out there that don't actually pay that much tax (profit tax) or taxes that are much changed at all by having some more business expenses - notably the fairly large number of businesses that don't show a profit or have "stored" tax losses from previous years, etc.
Anyway: "it's just a tax write-off" for something that's an expense is a phrase that generally communicates the speaker has no idea what they're talking about (or deceiving themselves) rather than some deep insight into how business works.