Although "inexpensive" is indeed a relative term, you have to factor in the context. In this neighborhood, 1495.00 can truly be considered such.
If you were talking to your buddies at the bar on a Saturday night, a fifteen hundred dollar amp would probably not be considered inexpensive. Know your audience.
Although we appreciate your advice on when (never, it seems?) and when not to use the word, we are all adults here and can figure out how to apply it’s relevancy.