Plan to quit during Pre-site stage

Hi guys, I'm in the pre-site stage with Metricon at present, waiting for the final draft and colour selection- meaning I have signed the preliminary contract and got my soil test result and finished with the structural plan for the house design.

I am thinking of quitting due to hearing complaints from people about the quality of the build and hidden costs (estimated 100k more for upgrades and site cost).

Can I still walk away and find a different builder without paying extra cost? After I signed the preliminary contract for soil test etc, I couldn't remember being handed over with a lot of details.

Please advise. Thanks!