If you’re a developer look at starter themes such as underscores, this is free. For plugins outside of the free ones within the WP plug-in directory, you should be scoping the requirements of your clients sites, researching the best premium plugins for the job and then factoring that in to the cost of the build and quote accordingly. Don’t try and be ‘cheap’ either, it is unsustainable I promise you.
Theme forest
If you’re a developer look at starter themes such as underscores, this is free. For plugins outside of the free ones within the WP plug-in directory, you should be scoping the requirements of your clients sites, researching the best premium plugins for the job and then factoring that in to the cost of the build and quote accordingly. Don’t try and be ‘cheap’ either, it is unsustainable I promise you.