Good day ,
I can do this . I worked a lot with mikrotik hotspot.
Is used Mikrotik login page ? or custom ? (if is custom price can be just 100 ) I can't check if address is correct 100 % :( , but I can check if looks like an email address - asdf @[login to view URL] .
Look forward to do this project .
In future you can use FaceBook like for login. in this way you can get more data from client . i.e. Birthdate, Email , Country.
Thank you,
Octavian