The term “spaghetti Western” is often used (not, mark you, by the OED) pejoratively, or at any rate superciliously, implying a cheap (i.e. trashy, not just inexpensive) movie. Such movies were not always either cheap, or of poor quality. The movie mentioned by Eyehawk, for instance, had in its cast H. Fonda, C. Bronston, J. Robards --- i don’t know if these actors were to be hired all that cheaply. As for quality --- well, spaghetti Westerns are a genre all its own, very easily recognizable. You may not care for the genre, but that doesn’t disqualify it.
Lots of spaghetti Westerns are truly awful (so are thousands of movies of every kind), but the fact remains that most REALLY bad Westerns have come out of Hollywood --- some of them anything but cheap, too. Nonetheless, one of the most godawful bad Westerns that i ever saw was actually German: “Flusspiraten vom Mississippi” ("Pirates of the Mississippi") . A sauerkraut Western, I suppose.