the lawns of all the houses in the subdivision were planted with cheap Bermuda sod.
The sod used by builders is cheap because it grows easily - not because it is a substandard variety. It is usually Tiff 419, a very nice grass and much MUCH nicer than seeded varieties of buffalo. I believe the seeded buffalo will not stand a chance in the Tiff.
Can a thick healthy lawn be made with Buffalo?
It absolutely can but it absolutely cannot from seed. It must be a sodded variety. There are two excellent varieties - Tech Turf and UC Verde.
Should I just ignore the native species and use Zoysia instead?
Ignore both. Zoysia has other issues such as being prone to disease and the inability to restore itself in less than 6 months from being killed off.
Zoysia is looking more appealing now because over time it will crowd out the Bermuda that is there now.
I am experimenting with zoysia next to bermuda. They blend well but bermuda is the dominant of the two. Why? Because the zoysia takes 6 months to recover from a drought while the bermuda takes 6 days.
Search the Internet for a document titled, The Bermuda Bible. Read it. Memorize it. Learn it. Follow it. You can turn your bermuda into a showplace with some work.