I don't feel sure about value (as I do not have .io personally) but given short and as you say pronounceable I think it has definite value. There have been 750 sales of LLL .io domain names with an average price of just under $1000, at least on NameBio. A few of the high ones were also 3 letter words. I would probably price it something like $1999 but take anything $950 and above, and consider I did alright with it (depending on acquisition cost). Given the high renewal cost, would try to move enough on price to sell it without too long a holding period. Best of luck with it!
Bob