Looks like there are some combo tickets to Dream World that include admission, lunch, and shared transport for cheaper than I would pay using Grab. But they are sold out for the transportation ones on the official website.

I see Klook, Trip.com and some other companies sell the same combo tickets. Is any one of them more reliable than the others?

Klook seems a little sketch, but I remember having to use Klook in Japan to buy Shinkansen tickets because the official website/app wouldn’t take foreign credit cards. And it worked out fine.