I love inexpensive/free typefaces as much as any other graphic designer (or maybe more), but it’s another ethical grey area sometimes, as many free fonts are a barely modified version of well-known typefaces, such as Futura and Helvetica. But although some are blatantly copied fonts, others are unique and somewhat well-designed. Even when this happens, the kerning usually has to be adjusted. That is, just be careful if you’re looking for an inexpensive alternative for your next design project.
As an alternative, there are also type designers who will release certain weights of their new typefaces, and there are also blogs that will feature when events like these happen such as Abduzeedo’s “Friday Free Fresh Fonts” (although most of the fonts aren’t exactly “fresh”). Really, the designer has to use their judgment in deciding whether a font is well-designed or not.