Ahhhh missed Spider-Man.... hulk smash!
The mission structure is exactly as you describe, but the combat and web swinging is a massive amount of fun. They have clearly tried hard to make the missions varied and interesting too. It's much more humorous than most games too. If you like superhero stuff then you'll enjoy the story . If not, maybe not so much.
I would bite their hands off then report them to Ebay
It's nothing new, no, just very well done. Story is good but if you're bored of similar games you'll likely be bored of this quickly too, depending how much you like swinging around virtual New York.
Ive seen a few copies with other sellers on ebay for around a tenner? do we suspect they are snide?