A button lock knife is very popular. Many are well under $100. I’d recommend the CJRB Pyrite Alt for a blade shape more similar to a razor. if you want even smaller the Mini Pyrite Alt is a great 5th pocket carry. https://www.knifecenter.com/kc_new/store_store.html?steel=AR-RPM9&style=Wharncliffe&usrsearch=pyrite&sortType=priceAs
You did the scales? Those look nice.