If you're a pessimist you say: "I bought a used amp for $2000 and sold it a year later for $1800, so I 'lost' $200.
If you're an optimist you say: "I bought a used amp for $2000 that retails for $3000, then sold it a year later for $1800. So I'm still $800 ahead.
If you're an optimist you say: "I bought a used amp for $2000 that retails for $3000, then sold it a year later for $1800. So I'm still $800 ahead.