Rapha isn't relatively expensive if you compare to similar high-end brands. Roughly the same as Castelli, give or take. But of course in absolute terms they're all expensive, but that really depends on what's affordable to you, how much you ride, and how much you appreciate any differences to less expensive equivalents.
What I HAVE learned over the years is that nothing is as expensive as that which I never use.
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"This 7:48 cycling session burned 5933 calories. Speed up recovery by replacing them with a healthy snack." - Whoop