I'm shopping for the Apple Mac Pro

Question

I'm shopping for the Apple Mac Pro Desktop 2.66GHz Intel Core 2 Quad, 3GB RAM
Mfr. Part # MB871LL/A
When I put that in the Apple website, (just MB871LL/A ) or Google on the Web, it shows results)
which on the Web is :
2300$ at PC connection, J&R and Amazon
While looking for a better price I found one
for much much cheaper (+/- $500 less)
Desktop Computers » APMP266QC3 » Apple Mac Pro Desktop Computer Workstation (Early 2009)
(I don't know why they call it a workstation ?)
They say all our products are new, not refurbished
It's the same as the one seen on J&R, Amazon, etc. but what bothers me is that the Mfr# is different. [APMP266QC3] when everywhere else, including Apple store, it is MB871LL/A
I'm wondering if there's something fishy here ?

Answer 1

First a clarification: After reading the May 2009 issue of MacWorld (pg 50) I decided to buy the Apple Mac Pro Desktop 2.66GHz Intel Core 2 Quad, 3GB
I find out that this model is known as Mfr. Part # MB871LL/A
So if I see a Mfr#Z0G8-0002 (see below) I'm wondering what it is.
The store that I'm talking is not B&H, it's on the other side of the country. They sell a 3GB and a 6 GB.
they sell a 3GB computer with # [APMP266QC3] which seems now to be a B&H stock # (No information on Mfr#)
They have also a 6GB and it has the APMP266QC6GB and
Mfr#Z0G8-0002 also with $500 less than anywhere else.
Both these number can be seen in B&H
And that's my question: Mfr#Z0G8-0002 ? (not sure what is 0002)
A completely different number just because 6GB instead of 3GB and everything else is the same ? That would be stupid. Usually it would just have one digit different at the end.
When I put that number in the Apple page it said no result found. (but that could be because they stop selling it ?) If you google it will show results.
I google both ZOG8-3GB and Z0G8-6GB
http://www.google.com/search?client=safari&rls=en&q=Z0G8-6GB)&ie=UTF-8&oe=UTF-8
http://www.google.com/search?hl=en&client=safari&rls=en&q=Z0G8-3GB%29&btnG=Searc h
or
http://www.epinions.com/MacDesktops--price_range_20006000
The first one compare to the 4th one. Ignore the stores. I'm not buying from them. I just want to show both computer on the same page.
Again, they have a different manuf. number. Is it just because it's 6GB instead of 3GB ?
So a store in the West, with no affiliation that I know with B&H in New York, sells a computer with a BH stock number ?
I know the saying of "if it's too good.."
I checked with the BBB there's no complaints about this company.