As usual in the install game , its always the bottom line , so I would quote the job without DDA compliance in the main quote . However I would then show a separate indicative cost on an individual sounder strobe.
Do not price yourself out the game by giving to much information , you need to be correct in what you say , but big totals at the end of a quotation is what people tend to look at.
If you didn't do the design on this job , its down to the designer to quantify the equipment.
What you need to remember that in a perfect world it will be 'eggs for eggs' .
Do not over offer information if you haven't been asked to do so , don't take me up wrong in this matter , if the client wants a system , get a specification completed and then obtain prices , it is always apparent that they are told to get 3 prices , and they are not like for like .
You have therefore made them aware that you are offering compliance within the system , you are not in a position to know what they are going to do with DDA , they might decide on 10% of the rooms will have beacons , and let these on that basis , you will be way out on your quote otherwise. Bearing in mind if there is no spec , you are deciding risk assessment on this matter , you should be paid for it.
Just a reminder if you are going analogue , think about the detection in bedrooms , dont get a system that you cannot turn of the pulsing led of the detector , as I have seen more than 1 system ripped out because this keeps people awake at night , so don't snooker yourself , you have probably thought of that already , but just in case.