These are rare enough to say that they don't come around very often, or ever! So I guess the selling price is very fair.
This set of leg irons had a high bid of $770.67 (Plus $8.15 Shipping).A super pair of early Handcuffs / Leg Irons in excellent condition with minor wear from use. The cuffs work well with the original key. - eBay (25 June 2012)