Can you provide an overview of real transactions?
I will suggest you do your own research (as for any service). Nothing can sufficiently explain a service to you like personal experience.
In the end, you are part of a promotional campaign. It is to be expected that you test the service you are advertising, at least once.
For example, I want to mix 0.002 btc, what is the total cost I have to pay for network fees and simbad service fees? Do network costs also depend on network density?
The calculator on the site, which lucifur also mentioned, is quite adequate and will give you a precise calculation of the cost of the entire transaction. You can use it even without finishing the whole mixing process.
The only thing that affects the current state of the network is the transaction fee you will pay when depositing on Sinbad.io
So, for your example, if you send 0.002 BTC, using a 1% service fee, the math looks like this
0.002 - 0.00002
1% mixing fee - 0.0002
service fee per each address = 0.00178 BTC
note: Si
nbad, not si
mbad