If your concern is about the lack of experience and therefore the inability to command a high rate, I would still recommend a minimum of 4k or 5k for this assignment (which is relatively low given that the images will be used for advertorial purpose which means earning potential for the clients).
In the end, you are going to shoot more than 4-6 shots simply because your client may not have an idea of what constitues the 'right' shot for each different perspective. Technically, they would be looking at your output (on the camera or on the notebook if you bring along one) right after each press of the shutter. Every one single view would constitute a probability of your client changing his/her mind and adjusting to a different angle. At the end of the day, 4 to 6 shots may end up with say 20 to 30 counts of shutter lifespan being depressed.
You may end up shooting say 3 hrs ('minimumly' speaking) to 6 hrs (high probability), which can be quite taxing - arranging the place, adjusting the model posts (if any), lighting, etc etc. Don't forget the loads of equipment you have to carry. Also, since it is a night shoot (after 9pm), you are likely to need extra sets of lightings to help with the shoot (unless you are really relying on white-balance corrected and long exposure shoot - works fine if no models are involved but picture normally end up softer)
And the efforts goes on after the shoot to produce the picture with some digital retouching ...
Oh yes, since it is after 6pm, it means overtime and therefore justifying the need to charge for more... Btw, if the client says something about putting your name on the pictures when it is being printed will aid in building your portfolio, well let's say money matters more (though other may differs).
Cheers!