We've had a few threads about this. It seems this is more common in New York State than in most places but people are loading 1,1 and 2,1 mac pros with pirated software and asking very high prices. The sellers tend to know very little about the mac pros themself and often make misleading statements.
Among the common misleading statements are:
"It has the max possible ram" or "the ram has been maxed out" - (they really mean the ram slots are full with small amounts of ram ie: random ram that totals to far less than the max supported ram)
They almost always claim the mac pro has Mountain lion when it really only has lion (in the case of early mac pros, mountain lion isn't even supported). Or they claim if they know something about macs, they claim it has snow leopard but it actually has leopard.
"it has $4000 worth of the best design software possible, a design studio's dream!" - If they won't include the dvds or appropriate licensing documentation, don't buy it.
Also, only a fool wouldn't reset a hard drive to factory standards before selling it and a fool wouldn't reset a hard drive to factory before buying it.
"Tons of blazing fast hard drive space!" - almost always a couple TB of failing 5400 rpm hds.
blah blah blah super fast GPU - Generally bad gpus, failing gpus, incompatible gpus, or just the factory gpu.
Of course, like half of all craigslist ads claim a computer is very snappy or very fast. Rarely is this the case.
Almost everyone claims a 1,1 mac pro they're selling is actually a 2009 or 2010.
They often mislead about the number of cores.
It's a mac pro! (it's actually an old G5)
Really a lot of this comes down to the fact that many mac pro buyers on craigslist are not well versed with computers and not pro users. People are attempting to take advantage of the ignorant.
http://buffalo.craigslist.org/sys/3560670939.html
This guy claims its maxed ram but he's got random low increment chips (random ram totaling 9gb). He claims it runs mountain lion but its running lion (as per the picture). He claims it has 2 blue ray drives but he has 1 factory super drive and 1 blue ray drive (as per the picture). None of the software comes with any documentation to support its properly licensed. He claimed it was a 2009 or 2010 model, it's actually a 1,1. A few weeks ago he was asking $3,000 for it.
Be VERY VERY careful when dealing with mac pros for sale on craigslist. They seem to be the item people are looking to take advantage of others with.
Ask questions, be suspicious. Ask for more screenshots from the system report. I occasionally will contact a person from 2 email addresses. I will ask different types of questions. 9 times out of 10, if you suspect something is wrong, something is very wrong.