Being a cheap bastud and a used tool junkie, I feel obliged to point out that in my experience, I would have to bat around .200 on used hand planes to make it worth buying new. Especially when compared to Lie Neilsen new prices.
I can buy five No 7. jointer planes at $70 a piece off Ebay for the price of a new Lie Neilsen. You do take your chances, but chances are you will come away with a very good tool before you spend Lie Neilsen money. You can further increase your chances by buying from a reputable used hand plane dealer.
I can't comment on how much the frustration of buying a lemon is worth to you. But it warms the cheapest cockels of my heart to know that I could buy a brand spanking new replacement for every one of those lemons with the money I saved.
That's my .01 cent worth. (Too cheap to give .02 cents worth)
Neil