Gambling is a very competitive niche. The idea is good, but a site with a domain is just a very small beginning. There is still a lot of work to do to bring in visitors and make the site respectable among gamblers.
Plus, it's ok to do everything in Laravel, but that pretty much limits the potential number of customers. Whoever would take this on, would have to be familiar with Laravel for later maintenance. Marketers who are good at affiliate, SEO and similar things will prefer to choose a more automated platform and reduce the time spent on coding.
Anyway, good luck with the sale.