Are these take-apart dinosaur rex toys worth it?

Here's the bit the listing buries: this isn't really four dinosaur toys, it's four dinosaur kits. Each Tyrannosaurus, Triceratops, Parasaurolophus and Velociraptor arrives in pieces, held together with small screws, and comes with a low-speed electric drill plus manual screwdrivers to do the actual building. The drill matters more than it sounds: full-speed power tools strip small plastic screws or spin too fast for little hands, so a slowed-down motor lets a 5 or 6 year old actually finish the job instead of watching a parent do it. Once assembled, the joints at the head, hands and feet still move, so the dinosaur isn't locked into one static pose, it gets picked up, taken apart, and rebuilt into a different stance the next day. That's the whole trick: the play doesn't end when the dinosaur is built, because building it is the play. The ABS material is sturdy enough to survive that cycle of assemble, pose, disassemble, repeat, which is really what you're paying for here, not the finished shape on the box.