Just a tip with buying a computer on craigslist. The listing price is what the person dreams of getting. From experience, the person will generally take just over a third of the listed price.
If there is no manufacturer warranty and the machine has been used or unused for long periods of time, the risk is far greater to the buyer that the machine will fail tomorrow. The seller must acknowledge that fact.
The older a machine gets, the less capable it is likely to be of handling new features, software, workloads, and media. The seller must acknowledge that fact.
The seller is ultimately looking to get rid of the machine they have, whether it is to get their hands on some money, clear out a machine they view as obsolete generally, or obsolete for their needs. The seller must acknowledge that fact.
A buyer that is comfortable letting a few machines pass, is a buyer with most of the leverage in all used computer negotiations. Both sides must acknowledge that fact.
Some folks will probably disagree with me but if you keep that information in front of you, you're probably going to negotiate far more realistically.
I regularly find friends able to buy 2007 minis for $100 and that is often with the seller asking for $250-$450 initially. So remember that just because you see people asking for $300, that does not mean they're actually selling them for that price.
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This is the information with the CL post:
Processor 2.3GHz dual-core intel core i5
Memory 2GB of 1333MHz
Storage 500 GB
I use a KVM switch with my computers. I share my monitor, keyboard and mouse between the computers. So I'm not really looking for a keyboard/mouse or anything fancy. It costs about $570 through Apple without accessories.
I bought a wireless logitech mouse and keyboard combo for like $13.00 on a newegg sale.
If you find a good monitor for sale for a good price, it might suit you better than a kvm switch, especially since you can buy decent quality mice and keyboards for so little.