IPA: //ˌʌltrɪɡˈspɛnsɪv//
KK: /ʌltrɪɡˈspɛnsɪv/
Very high in cost or price, much more than what is considered normal or affordable.
The new luxury car is ultraexpensive, costing more than most people's houses.
Ultraexpensive → It is formed from "ultra-" (meaning beyond or excessive) and "expensive" (from Latin "expensivus", meaning to weigh out or pay out). The word "ultraexpensive" means excessively costly or beyond what is considered expensive.
Think of 'ultra-' meaning beyond, and 'expensive' relating to high cost — so ultraexpensive means something that costs way more than usual.