Storage Cost Calculation

Steven D'Aprano steve+comp.lang.python at
Sun Sep 28 06:39:28 CEST 2014

Chris Angelico wrote:

> On Sun, Sep 28, 2014 at 12:47 PM, Steven D'Aprano
> <steve+comp.lang.python at> wrote:
>> But no, you can't put the £100 difference down to the price of the RAM
>> even if RAM were the only difference between the two model Micros.
>> There's not enough information to tell how much of that £100 represents
>> the cost of RAM, and how much is pure profit on the part of the vendor,
>> Acorn. In fact, there were considerable differences apart from RAM:
> I don't care about "pure profit on the part of the vendor" - that's
> part of the end-user cost of RAM.

No, it's part of the end-user cost of the BBC Micro model B. What we want to
know is the cost in 1981 of buying a 16K memory chip, without the rest of
the computer.

Even that's not necessarily a good indication, since there are all sorts of
things which could distort the price. Historically, both IBM and Apple are
well known for (ab)using monopoly power to keep the price of spare parts
extremely high. If (say) Acorn charged £85 for a 16KB memory chip, while
other manufacturers charged £15, we wouldn't want to treat Acorn's prices
as "the cost of RAM in 1981". We want to compare typical, competitive
prices, not RTBO ("Rip The Bastards Off") prices.

I used to work for a company that made and sold electronic sensor taps.
There were four components: a spout, a solenoid, a transformer, and a
sensor. If you bought the four components individually, as spare parts, it
would cost you about twice as much as buying the entire kit. Some of that
reflects the fact that there's about the same amount of overhead (ordering,
billing, storage, packing, delivery...) whether it's a $300 kit or a $30
spout, but most of it reflects monopoly power. When selling the kit, we
were competing with other brands of electronic and hands-free taps. When
selling the parts, we had a monopoly on the parts: other brands of parts
wouldn't fit our taps, and our parts wouldn't fit theirs. I don't quite
remember the exact figures, but markup on the entire unit was about 30%,
and markup on the parts were about 100-200%, I think.

And this is partly why, for a long time, Apple spare parts were so much more
expensive than non-Apple spares that wouldn't fit in your Macintosh. You
had a choice of RAM from three or four manufacturers for your PC, and no
choice at all for your Mac. (I don't know if this is still the case now, I
haven't used a Mac seriously since System 7.)

> But if my presumption is incorrect, 
> there's no way to put a price on just the RAM.

My point exactly :-)


More information about the Python-list mailing list