Res tantum valet quantum vendi potest

A thing is worth only what someone else will pay for it

Respice finem - Look to the end
Respice post te, mortalem te esse memento - Look around you, remember that you are mortal. (Tertullianus)
Respice, adspice, prospice - Examine the past, examine the present, examine the future (look to the past, the present, the future)
Respondeat superior - Let the superior answer (a supervisor must take responsibility for the quality of a subordinate's work)
Resurgam - I shall rise again
Revelare pecunia! - Show me the money!