Up-selling, despite what some people believe, is not a sneaky or dishonest sales strategy.  In fact is is an essential strategy for start-ups.  I do, however, understand, how many people can see it this way.

At the bagel store near my house, a bagel costs $0.49.  Yet, order that bagel with $0.03 worth of butter, and the bagel is suddenly $1.69.  Why does the store do this?  Because its great to advertise bagels that cost only $0.49, but who comes into the store and only orders 1 bagel with nothing on it?  The upsell is the critical method of driving profit into the store.