Imagine on how much that 1000+ btc cost and if you do know you can open it then 1BTC price of the hard drive is just a piece of dust but the question is,
do really have that harddrive with btc on it? No one will buy if password still cant be remembered.
If there was a way of proving there is Bitcoin on that hard drive and he could demonstrate he is the rightful owner then a 10 character password could be bruteforced especially if the bruteforcing was left for a number of years because that amount of Bitcoin is worth the time and electricity costs that come with bruteforcing it.