I am surprised you are not aware that there is always a budget and time cost in any project that you take. This applies to everything and not just programming. I am unsure if you are asking why budget and time are important constraints or are you saying you can spend $$$ enough to ignore these constraints?
Adding an SMS notiification is easy if you know how to do it. It's all relative to the person doing it. I know folks who can't even read the manual or do a basic recursion.
If I am the one wo4king on your thesis, here's hkw I would estimate this project.
Overall difficulty:
- Arduino programming: Easy. I have done tons of Raspberry and NodeMCU projects
- Hardware tinkeing: Easy as well due to above
- Web programming: In general it's easy. I can make ir as difficult as I want if I wanna make things really complex or easy if I just wanna slap a simple UI
- API integratikn: Easy too. I have done Twilio integration and also done a couple of projects that use SMS to send notificaitons when someone enters the house or any microcontroller based triggers.
Budget:
- Arduino plus tools. Probably around $200 or less
- Electricity measuring device: This is unknown for me. I will have to reseach how much it cost here in the US and if available. What exactly am I measuring? Power from a small device or from huge generators?
- Since I am not student, i will charge this project on my hourly rate of $70.00. Yes, $70 USD. I told ypu it's all relative.