You may be able to (entirely legally) part out the sets on bricklink, buy the generic bricks from webrick, and buy the specific bricks from bricklink sellers. This will be substantially cheaper and it’s an onboard into non-Lego building bricks which have gotten really good in the last few years. The glut of vendors selling copied Lego sets has given the field a bad name, but the brick design is out of patent and there are many sellers designing their own sets as well as selling MOCs.