Is a Raspberry Pi (Neblio) staking node profitable?

I'm staking with Raspberry Pi's because it is not worth it to let my PC open 24/7 (because of the high power consumption).
Some Pi's where a present or i bought them very cheap like the Zero for €5 and a USB WiFi stick for €1.5.
Still is it profitable to run a node like this? So i made this overview with Neblio as example.
The amount of coins is also an example and not mine quantity. I hope to make a post about my staking Pi's on 1 January 2020 to give you an example how much all the coins stake(%) in a year.

So here is the part list i use for my Neblio Pi Zero.

Part	Price (€)
Pi Zero	5
SD card (16GB)	4.5
USB WiFi	1.5
Total	11

The power supply is a simple micro USB so i hope you have one lying around. You don't need to connect this Pi to a monitor or keyboard with this post ( https://steemit.com/crypto/@cryptoraspberry/skyminer-node2-headless-pi-installation ) that saves you money because you don't need a mini HDMI -> HDMI converter.

When we buy at this time (16 february 2019) 200 Neblio(€0.945) for €189 and we pick the €11 for the parts we run this staking machine for €200 total.

This calculator : http://nebliostats.com/calculator.php gives us the prediction of staking a year.

This is not 100% accurate so lets say that we get 20 Neblio in a year.
That's €0.945 x 20 = €18.90.
So with this small amount we can get the €11 back in a year. Need to mention: you don't know the price of 1 Neblio over a year. When it goes down you can have less, when it goes up you can have more :).

When we also check the power consumption:
1 Pi Zero takes 0.75W (high speculation based on this site: https://www.jeffgeerling.com/blogs/jeff-geerling/raspberry-pi-zero-power)

0.75W x 24 (24hours a day) = 18 watt-hours per day
18W / 1000 = 0.018kWh (1kWh = 1000W)
0.018kWh x 365 = 6.57kWh a year

When you can get a kWh with taxes for €0.22 it is : €0.22 x 6.57 = €1.45 power consumption a year.
So this is it:

Part	Cost first year (€)	20 Neblio staked (€)	Total profit first year
Pi Zero	11	-	-
Power	1.5	-	-
Total	12.5	18.90	6.40

With the +/- €18.90 you can cover the startup and power cost with staking :).
I do not mention the €189 from the coins because when the price is the same (not likely) in a year you still have this money only converted from fiat to Neblio.

So do you think it is worth it? Do you run a staking machine? Please tell me :) i love to hear from other stakers :)!

Links:
GitHub Neblio (how-to): https://github.com/NeblioTeam/NEBL-Pi/releases
Headless installation: https://steemit.com/crypto/@cryptoraspberry/skyminer-node2-headless-pi-installation
Power consumption Pi's: https://www.jeffgeerling.com/blogs/jeff-geerling/raspberry-pi-zero-power
Neblio staking calculator: http://nebliostats.com/calculator.php