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Idk, if you're looking at Amazon, everything is like $20-35. The nub is super inescapable and comes in pink, and I also really like the metal cage below, but I have to tie a string around it since it's heavier.
Hope that helps!
Raycity Male Chastity Cage Device (40mm Ring) 119 https://www.amazon.com/dp/B01JHV1NSA/ref=cm_sw_r_cp_apa_i_-IIWDbM3WK77T