In Singapore context, there is no way for landed to be cheaper than condo given the same location and tenure. Simply because you are sitting on your own land which is scare.
999 and above lease hold land are hard to come by. the only opportunity to turn around are older condo sitting on such land. that is why you see more transactions. if you look at bigger land area, like bigger apt, the psf cannot be proportionally going up with exception. just check out the real transaction you will be able to confirm this.
On paper, there is an apparent difference in 99 years versus 999years/freehold title.
In reality, especially in Singapore, I find it less of importance. Why?
1. It is true, there are some 999/freehold condo selling cheaper than some HDB flat in terms of per sq foot. In addition, there are some 999/freehold condo renting out cheaper than some HDB flat in terms of per sq foot and availability of amenities including carpark spaces. There are many 99years leasehold property selling more expensive than 999/freehold condo especially in the Pasir Ris area.
2. Most of use are not expect to live beyond 99 years and if we do, likely we cannot differentiate ABC from 123. By then policies would have changed as not just a few but many households will be affected by the end of the 99year lease. In many other countries, it usually involves a token sum but in Singapore, I hold my reservation.
3. Whether 99years or 999years/freehold landed property, it does not matter, if the government wants to take your land for whatever reason including making lonkang, it will be taken. The compensation, don't expect to be market rate, in addition, you have to bear some fees associated including legal fees for the acquisition. My garden was eaten by 1/4 because there was a need for suppose reason and was compensated to the advantage of the state.
So in short, in our life time (for most of us) we are not going to see the end of the lease be it 99years or 999years/freehold. Buy a property that is within your means, you will enjoy staying up to your ripe old age (Warren Buffet) and reasonable location with amenities should see you safely grounded.