You don't need a complex model to judge a domain. Three simple tests settle most decisions.
The phone test: when you say the name aloud, can the other person write it down without asking you to spell it? If not, you lose a little on every customer contact. Turkish characters and doubled consonants are what trip this up most often.
The sign test: does the name read on a shopfront, a vehicle wrap, or a business card? Long names mean small type, and small type doesn't read from a distance. Shortness is a functional choice, not an aesthetic one.
The search test: does searching the name surface a strong brand you'd be confused with? If it does, you'll live in that brand's shadow for years. Passing this test protects every marketing pound you spend afterwards.
A name that passes all three can look expensive. The cost of a name that fails never shows up on an invoice — it's paid over time.