If you're really concerned about the prices of the lenses, then look at 3rd party lenses as (often) cheaper alternatives. Although some of them may not surpass the quality of the OEM lenses, there are exceptional cases where cheaper 3rd party lenses (e.g. Tamron, Sigma, Tokina, etc) fair better than OEM lenses.
Unless, you're one of the crowd that suffers from the "no-3rd-party-lenses-for-me" syndrome, then the "original" lenses will be the only way for you.
All in all, as in all purchase decisions, research is paramount to determine what works best for your budget and needs.