The phrase "are exceptionally expensive" is correct and usable in written English.
You can use it when describing items or services that have a high cost compared to others in the same category.
Example: "Luxury cars are exceptionally expensive, often costing more than a small house."
Alternatives: "are extremely costly" or "are very pricey."
Insurance, which is exceptionally expensive for a building that houses irreplaceable art just yards from the Gulf of Mexico, has been negotiated down to its minimum.
He said LIPA would "try to accommodate the communities as best we can," but noted that putting lines underground was "exceptionally expensive" and complicated by easement problems and the difficulty of excavating in areas where other utility pipelines and cables were already buried.
The 45 billion-dollar roaming industry is a testament to the demand for staying connected while traveling – and yet roaming is exceptionally expensive, and disturbingly uncompromising.
It is exceptionally expensive to construct long-interval transmission lines to serve little groups, particularly when these groups are generally poor and cannot sustain to pay rates sufficiently high to take care of the expense of these power services.
Further, InFuse™, which was designed to deliver high doses of BMP-2, has been reported to have serious life-threatening side effects, and is exceptionally expensive to use.
The second uses PCR to attach an MID (Binladen et al. 2007) but is exceptionally expensive because it requires the purchase of long primers (35 55 bp, depending on application) for every combination of primer and barcode to match each sample used in the study (e.g., 12 samples × 12 loci would require a total of 288 primer pairs).
Although his businesses are exceptionally profitable by global standards, the services are slow and expensive, and their uptake low, even by Latin American standards (see charts).
Fairways are exceptionally narrow.
Quasicrystals are exceptionally brittle.
