Yes, it is indeed ulu. Not good for those who don't drive. Stayed there for 10 years and never really realized the ulu-ness until I started viewing other condos last year. Also, it was a marked improvement compared to Clementi Park which I stayed at for 15 years previously. The nearest supermarket to that area is either U-Stars in Clementi or the big Cold Storage at Jelita.
A major plus point is that the area feels very 'exclusive' and it is extremely peaceful and pleasant. No traffic noise AT ALL. Nice greenery, low population density, and no HDB around. Hard to put a dollar value on that. It is something I miss now that I moved to a busy area, though am now just a few minutes' walk to malls, supermarkets and MRT station.
As to why it commands high prices, well... In addition to what I mentioned above, part of the area falls within D10, and it is considered a private enclave.