Quote - I know that 30% off is a pretty good deal, but you're only saving 15 dollars or so and you've got to spend quite a bit to get that.

Exactly.
"Saving" is no more than a manipulative marketing term for what is, in reality, the precise opposite:
"Spending".
If I'm not prepared to pay the full price for something, I can't want it enough to buy it even when it's "on sale"!

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)