If you want really cheap
, make some out of some old halyards or sheets
(pretty easy with a few knots).. The catch is how much will it hurt if they truly arrest an overboard
event - the wider the straps, the less likely the injury. - still a cracked rib
or wicked bruise is better than drowning.
I'm not sure about the $10 harnesses you are talking about - be especially careful of the hardware
used - you want aluminum
FYI the black diamond one mentioned, and the one I linked to is less than $40.