NO affiliation, only sharing a source.
For those of you that have larger boats, Monroe Engineering in Auburn Hills, MICH has variety of offerings available & most are in stock. The ball locking ring handles in 304 stainless were running $17-$22 each at this time last year. That was for 1/4 and 5/16 diameters though. Give them a call for your specific sizing needs for accurate pricing.