how much would a deville cost?

what is the ceapest price i can find a cadillac deville?

That's a vague question! What year, mileage, condition and area are you looking at?

I bought my 1990 DeVille 260kms for $1000CDN.

the best place to get an idea for car prices is

kbb.com and autotrader.com

If you want to know what high retail is, take a look at EBay.

I thinking buying a car locally is best, because you can have a mechanic (or dealership) check it before purchase.