what would you question them about next time?
1) Do they really inspect each Mac before reselling it to us?
2) If yes, what exactly is involved in that inspection?
3) What exactly will happen if a Mac fails within the warranty period? Will I ship it back to them? Will I have it repaired locally and they reimburse me? What exactly will happen?
If they say that they really do inspect the macs carefully and that they will fix anything broken, I would then ask why that didn't happen with my last purchase. I would analyze the quality of response I get to that question.
I've bought 4 old macs from them, and all have been fine except for a jammed space bar on the most recent mac.
You might want to search out more stories of what happens in those cases when there is a significant problem within the warranty period. I really don't know, as I've only had one small problem.
Also, please keep in mind the great value that any used Mac is. You can buy 3-4 five year old macs for the cost of a one new one. Thus, I've concluded that buying used macs is actually the safest and most reliable way to buy macs, assuming you use a reputable vendor, which I believe macofalltrades to be.