Bike without wheels

Okay this might be a really stupid question, but I am stumped as to what is the answer.

When I was looking for a new bike I decided that I did not need fancy wheels as I already have a decent set, bought after buying my older bike, and a winter set, which came with the older bike. I have also got another average set that I had from some other bike.

So i was thinking why can I not just everything but the wheels, it would save me money and save me having another set of wheels that I would just change anyway. Thee must be a reason why this is not done already, but I cannot see any site offering bike only, no wheels. Any Ideas I reckon it must save, even at the cheapest and cruddiest wheels, inners and casings £100-£150. I know I could just order all the parts, but that’s a new build.