We have an "Egress Porch" off our kitchen dining area and did not wish to block the view. A local glass shop cut and tempered the panels. Did this quite a few years ago and don't recall the cost but it was reasonable.

I'm only familiar with one house with glass balusters, they were vertical glass pieces, maybe 2"-3" wide, spaced about 3"-4" apart.

This was a beach house. The idea sounded nice to the owners, but they complain about the glass being dirty. Dried salt spray, etc.

Similar to this:

Another alternative is cable railing. Some locales don't allow it as they perceive it as being "climbable". You'd have to confirm.

Here's an example of cable railing:

The number one complaint I hear about glass balusters is they get dirty, fast. Especially in places like mongoct mentioned, near the water, places with lots of rain, wind and dirt. If they have already proven to be expensive and custom I think that cable railing would be an excellent alternative.