Why buy Pentax camera if not getting weather sealed lens?

Hi,

I'm saving up and shopping around for my first ever DSLR and take some classes. I really like the idea of weather sealing on a camera, but the Pentax lens (the DA* I believe) that have weather sealing seem really expensive.

So I feel like if I buy a Pentax camera like K5, but don't get a lens that is weather sealed, wouldn't that defeat the purpose of buying a weather sealed camera?