Thanks for the link (I think). $50 is not cheap - I hope that is for the pair.
That is a relative statement. Figure your time and money to procure materials to make a mold and the pouring media. Then time and effort you have to have to procure a pattern to copy ? Coupled with the time it takes to make the mold and the time to make the part. At the bottom side of the balance sheet of time and materials the 50.00 doesn't look too extravagant
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