I scored the following domain today SecurityTokenExchange.org (There's even talk of a Token-Capital-Market, as debt and equity capital market assets become tokenized.)
Anyway, I got it from a GoDaddy auction for $12 bid, + reg fee. I found its listing on a deleted/expired domain search engine.
FreshDrop.com is a great go-to-place, as you can search all the registries, and define searches (from age, to page rank)
Otherwise, place a "Wanted-Domain" thread here, along with a budget, keywords or whatever, and negotiate people into giving you their best offers, as their will be competition for your money.
Hope this helps