Ladder Notes....scrambled

That's a spender.

I had a scrambled ladder note (US $20) that sold for $30 on ebay to a collector in France. Digits were 1 through 8. It's really hit or miss as to finding a collector though.

Depends on what you count as scrambled, really. I have a note with digits 7162534 - that's almost a perfect scrambled ladder (it's too badly bent/folded to be really collectible, but I definitely won't spend it); but I might not even notice a random permutation of non-initial digits like 4563987 in the OP.

Generally, the chances are like 0.15% for 7 digits (assuming 0 can't appear, because it's unclear on what side it is) and 0.08% (same assumption) for 8 digits (0.04% for 1-8 specifically). That's 1.5 times, 8 times and 4 times the chance of a radar, respectively (1-7 specifically in 7 digits will have about half the chance of a radar).

I was wondering if a scramble ladder note worthless or valuable serial number 40136725

Serial no-40136725, is too 'scrambled' in my opinion.

A spender.

Hmmm... reading this makes me regret spending a $20 a while ago, 0213456.