Hello, I am a experienced Web Developer with emphasis on gambling/casino style sites.
Cost will depend on the complexity of the project and the features needed.
Games I've built from scratch: Crash, Roulette, Lottery, Slots, Sportsbook.
You made a gambling site with just TS/GraphQL and ReactJs? Have you heard about a thing called a "BackEnd" or "Security" or "Servers"? If you're an experienced Web Developer, could you share links to your portfolio/gambling projects? I'm not going to get any benefits off that but will make this post more interested to be taken seriously but your potential clients.