Any insight on evaluating a misspelled domain for purchase?

[webmasterbeta]

Say there is a misspell for sale on a popular word. Hard to tell if anyone would misspell it this exact way, but looks OK. The actual correct word domain is there also just catching type-in traffic itself. No traffic figures available for either.

How would you guys appraise the name? Based on what parameter? Going price is just above the level at which you would purchase it anyway and then write the loss off if it did not work out.

Thanks!

D~