Have been an auto service tech for more than 15 years... this is no contest. Buy the Buick, a few problems here and there but proper maint goes a long way. That Chrysler was bad news from the word go.
As for the current ride. Find a busy corner and throw a sign in it. Take offers till one sounds right. It's just too hard to know what people will pay for stuff anymore.
Best of luck with the "new" ride!
Frank