Is it cheaper than just adding a little programmable clock onto the coop doors? I would assume you're not going to change the timing much anyway since chickens thrive on routine.
The electronics on the thing are not that expensive. It's just a little photosensor that by default goes at dusk till dawn. The programmable portion is to change the delay and light sensitivity. Since summer vs winter is 3-4 hours different a timer would have to be adjusted a lot.