One of the biggest opportunities I've missed was not buying a '71 Dodge Challeger 440 for $1500 back in 1987. ( it had a broken exhaust manifold )
My dad asked me: "Why do you want that car, so you can out-run the police"?
Those cars are worth a fortune right now.
I bought a Baja Bug instead which led me to where I am today, which is still OK.
KT