As far as WordPress themes are concerned, you usually get what you pay for. Support is worth every cent of your purchase. However, short of a full-price, full support theme, I’d rather use a free theme than a half-supported theme. There are actually some really good offerings out there.

In addition to my favorite mom and pop shop for free themes, builtBackwards, I just found this new collection of high-quality free themes, at Web2Feel. I’m not yet sure what the catch is, haven’t tested for hidden links or any of that, but their offerings look excellent, especially their tumblr-styled themes.  Let me know what you think of these, especially if you’ve ever used any.

Addendum: Found some promising WordPress child themes from WPCharity.

For security sake, consider using these sites for malware, base64, backlinking and exploit checking:  builtBackwards Theme Authenticity Checker Plugin   or   Donncha O Caoimh’s Exploit Scanner