200$ does not include gas and electricity. Plus is being used "as in addition to".
as in 200 dollars a week in addition to you paying gas and electricity (as in they are not included with the 200)
Unless there was something said before that said otherwise its not included.
As Hagowingchun says this excludes gas and electricity.
Another way of saying the above without using "plus" or "in addition to" is as follows:
The rent will be $200 a week excluding gas and electricity.