Hi Karl,
The mentioned project seems feasible to us. However, a more detailed analysis can be carried out afterwards.
We have done few projects like this for our Indian clients in Past.
In this mentioned cost we have also included the cost of hardware. We will also provide you with a basic Android application on which you can see the data obtained from RPi/Arduino. Also, in future as per your requirement we can convert this system to be an API, where a person can choose, whatever data they want to see on their dashboard.
We do have a few questions though:
1. Do you have some server space online where the data can be send and from where the website will be displayed?
2. If possible, can you please provide more detail on the programmable message.
As per our preliminary analysis, along with the below mentioned deliverables, this project will require somewhere between 50 to 80 hours (Although the actual may be less or more):
1. Hardware Development & Testing -> 25 to 35 hours
2. Web Backend & WebPage -> 5 to 10 hours
3. Android Application Dev & Testing -> 20 to 35 hours
The cost will be as per the mentioned houlry charge and will include the cost of hardware, however, the cost of online server space is not included (we can also help you get one if don't aleady have it on additional charges.)