Mike is right..That is a sizeable amount of images and a ton of work.
However I think like Mike if the job has no value to you as a future image and just for portfolio work then go for it.
I tend to think that no matter what the images are yours to sell.
It is purely professional courtesy to NOT sell and image if the client has requested and paid for the right to use it exclusively.
It is up to you to make enough money off that image to not have to sell it again.
That doesn't mean you cannont sell that image down the road after the client has "used it up" so to speak, but you will need to keep the client informed and aware that is your intention.
I think in a court of law the battle will be hard either way so just be respectfull of the client. If you have an opportunity to sell an image they paid for then get them involved. Maybe if they make a buck off of it also they will not get bent out of shape and you will keep a client.
I would ad in expenses though to the cost of the job.
It also sounds like this developer has worked with a professional photographer before.
To shoot out a price suggests he has an idea what this kind of work is worth.
You have a choice here IMO.
Take the money and run, enjoy the paycheck and use it as a learning experience to base future jobs on or....
Use this as a model to get your pricing in line with the market.
Remember whatever you do this is a client that will probably come back to you after you do a great job.
So what you charge today will be what you have to charge tomorrow or down the road.
I would feel him out for a "top end" then come down.
Remember he sought you out not the other way around...Ball is in your court now.
Fly Fast....Live Slow...