I'll Explain What I Look For In A Fish Scaler:)
This model i first purchased 10yr ago. It has a plastic cage to catch flying scales & is useful for cleaning fish indoors without flying scales sticking to the dog. There are units both on eBay & Amazon that are identical except they have no plastic cage for flying scales. Prices range from $20-60ea. The headings say Brass Fish Scaler From Japan.
I gave my 10yr synopsis of owning this scaler. It was either this or a pure steel unit from Shinjuku, S.Tokyo on one of my trips there (+$300US). Besides my analysis i scaled a Goatfish at 2:42 and a White Trevally Jack at 4:11 time frame using this scaler. No scales flying around & the fish were easily scaled.