Your experiences with buying off eBay

[wallaby]

Hello,

I am starting to pass between the realms of "want a new laptop" to "need a new laptop." I've been rocking this Macbook Pro (2.2Ghz, 4GB RAM, 48Gb SSD + 320GB HDD) for 8 years, and it's been great, but I am falling behind in a lot of areas:

• Battery sucks (3 hours if I'm being nice to it, but more often 1.5 hours of "normal" work)
• Large and in-charge (as in tethered to the wall)
• Constantly whirring up the fans to cool off
• Can't access the latest and greatest software (I'm on 10.6 and had a bad experience upgrading to 10.8 previously)
• Kind of big to lug around
• VirtualBox only barely works

I know the common advice is to wait for a laptop refresh (come early spring), but the problem is, I'm strapped for cash. I'm eyeing some ~$600 Macbook Airs on eBay and wondering:

1. Have you had a good experience buying Macs on eBay?
2. Has anyone regretted moving from a MBP to a MBA?

I'm not super worried about #2, being that this mac is old enough that even the lower-clocked i5's in the MBA line are 3x the speed of this thing. I would be sure to grab a 256GB model based on my current usage, which is a lot of web design work involving Adobe's full creative suite (and occasional video editing). I'd love to grab a refurbished model on Apple's website for peace of mind, but those currently start around $800 for just a 128GB model.

Alternatively, I can just stay at home tethered to my Windows PC and spend nothing.

Is buying a used MBA on eBay a good plan?