I was browsing on eBay, are these kits a worthwhile investment?

Dillon RL 550B/C Primer Track Bearing Plate Kit W/Ball Bearing 95056442041 | eBay
The tighter tolerances allows better fit over a wider range of Dillon 450, 550 and 550B than previous generations but still very adjustable for all generations of Dillon RL450, RL550, RL 550B and RL550C.
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