What is the difference between the sign for 'money' and 'buy'?
Both signs use the exact same handshapes, but 'money' involves tapping the back of your dominant hand into your non-dominant palm twice. To sign 'buy', you start in the same position but move your dominant hand forward once, as if handing money to a cashier.
Does it matter which hand is on the bottom?
Yes, your non-dominant hand should always be the base hand (on the bottom, palm up). Your dominant hand does the moving and tapping. If you are right-handed, your left hand is the base.
Can I just tap once instead of twice?
For the noun 'money', you should tap twice. In ASL, nouns typically have a double, smaller movement, while related verbs often have a single, larger movement. Tapping twice ensures you are clearly signing the noun.