I think 35 Ringgit is a fair and reasonable price for the KLIA Ekspress train. It takes 27 mins so is about 50% faster than a teksi, and costs about a third of the teksi fare.
I totally agree, and given the trains are mostly running very empty, and absolute relative bargain in the scheme of things. Clean, ontime, room to swing a cat. It is a no brainder , take the train, everytime. Oh, and the lifts drop you on the platform where you need to be - quicker than walking to the taxi stand, plus an amazing vista of Malaysia building activity going gangbusters. On a par with catching the bus to see the Spinx shopping centre, and the painted prison walls.
But remember, you have to get to Sentral station first, and that may be another teksi fare, and the time and hassle in the transfer process figures into the equation. Some of the other outer stations do not have elevators or lifts - issues for people of limited mobility.
However, in seeing a friend off, I chose to say goodbye at the station, and skimp on on a return trip to talk a bit longer (as did a lot of others). I think they should introduce a 35 rt round trip companion ticket.
KLIA has one huge advantage over most other airports - it is friendly to old / frail people, and people in wheelchairs. I don't recommend BKK anymore, as the new airport there causes the oldies to do a 1000 metre walking detour via overpriced duty free shops, to get to the gate, the cough airconditioning, bad facilities, and lets say certain fatal construction faults.
Can't wait to visit Malaysia again - great value, and friendly to old pensioner sorts, as long as they don't visit the bus station, that feels like 100 degrees plus inside, I nicknamed it Hells Oven - another must see to believe place.
On bus transport I think I paid some 60 ringgit for a luxury 'SNOOZER' 24 seat bus to Penang - the bargain of all time for a 4 plus hour journey, then 100 rt on Penang for a 20 minute taxi ride.