$ grep -r chmod .|grep 777
./app/Mage.php: chmod($logDir, 0777);
./app/Mage.php: chmod($logFile, 0777);
./lib/Varien/Autoload.php: @chmod($this->_collectPath, 0777);
./lib/Varien/File/Uploader.php: chmod($destinationFile, 0777);
./lib/Mage/Backup/Filesystem.php: chmod($backupsDir, 0777);
./errors/processor.php: @chmod($this->_reportFile, 0777);
I can't say what we're paying for this standard of quality, but I can say that it's public knowledge that Magento is at least $13k/yr.
The Magento world doesn't seem to consider this in any way a problem. Every guide I see blithely says to 777 stuff in your bloody webroot. I CANNOT EVEN.
Also, storing money as floats is absolutely fine and defensible.
You know you've been working on Magento a bit long when you can hum along to bits of "Metal Machine Music" accurately.
Update: Holy crap, this comment.