Hi scooby. Same as you, i also go by the flight and taxi/bus combo. Just a matter of preference.
Anyways...
1. Grab "normal" is pretty much standard price ~ rm149, toll is about 10ish. So total was rm159.60 for me. Or you can bus to kl sentral for 13 rm is it? And grab from there to rwg for some 90ish. That will shave off another 50ish rm. I am lone traveller so if you are travelling in group, grab will be more economical. Do note the car is usually the non premium type, and will have (minor) prob climbing the slopes.

if wanna slightly more premium with guaranteed 5 star driver, not necessarily 5 star car, then theres the 248 option but i strongly advised against that. Not worth it. I dont think below 5 star will necessarily wanna be gungho and drive dangerously. 5 star and non 5 star lives are just as precious.
2. Or you can book from klook for some 73 sgd. Better service, driver waiting for you at arrival and all...etc. Havent tried before. Do update here if you opt for this.
For my return leg, i do the skyway, aerobus option. Aerobus to klia rm35. You can do the same for you outbound . For me, i opted for grab to rwg cos i wanna kiss my slots machines quicker, which isnt true by the way...takes almost same amount of time. The wait for the grab can be up to 15min cos apparently they need to meander the imaginary traffic congestion.
Hope this helps.
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