When he goes to the convenience store to buy 1/2 gallon of milk he gives the clerk a 10 dollar bill and she gives him 25 cents change.
Mountains with Saguaro cacti are seen in numerous sunrise scenes and Lucky takes a walk down a road and stands under one. Saguaros are native to Arizona, which is where these scenes were shot, but the town Lucky lives in shows large mountains with no Saguaros. In Arizona, the desert geography changes gradually, so it's obvious the town scenes were filmed in a different geographical location.
When Lucky is in the bar, a reference is made to the Saguaro cactus outside his place. Saguaros are native to Arizona and are rarely seen outside the state unless they were dug up and transplanted. Later, when Loretta shows up, he is seen watering a cactus, which is actually a succulent.