clickhappy

Say you have a dating website and need a mobile version. The only functionality you need for mobile version is:
1. Ability easily log in
2. Ability for users to easily see if they have a message
3. Ability to send and receive messages
4. Ability to see who else is nearby
5. Ability to search easily.

And thats it.
How much do you think a mobile version of that should cost?

This is not a full app, just a mobile friendly version.
I just want to know if the estimates I got are realistic