Would coins be a good investment?

If I bought 2006 silver eagle proofs.
or if I bought 2006 gold eagle proofs?
Back in 1991 I bought $100 worth of non-proof silver dimes/half-dollars last week I sold them in the rich part of town. She gave me $100 for them So anyway would proof silver/gold coins be a good idea? Any help would be great..Thank you!