Why does a shifter lever for this car cost $650 in Canada and $180 in the USA? on 2007 Cadillac STS

A $20 sensor requires a whole new part # 19179517. Prices for repairs for this car are insane. Four air shocks were $4,600 installed @(50K miles). Rear tires are different than the front. Gas mileage is poor and I have spent over $7,000 on repairs for a car with <66,000 miles. Have >250K miles on a 1999 Camry and repairs were under $1,000. last Cadillac I will ever own.

Asked by for the 2007 Cadillac STS