Well,
The domain name is great. Its a popular word "walked". Immediately the first issue is the past tense. I think the "ed" really keeps this one grounded in terms of value. Its a nice domain regged in 99 - most other TLD's taken.
A large indicator is the amount of searches the keyword "walked" gets, and its under 500 per month. Making this not quite a traffic domain name, even if it were indexed high.
I could see it being sold in the 7k-10k realm to a reseller, perhaps an end-user like Nike or another Shoe company would see a higher value in the $15-20k range.
Nice domain name,
Justin