Hello Tomilio... all good questions!
1) If the cost is so important (and not the experience, or the quality of a good espresso), then you shouldn't consider such a machine.... (but then Nespresso is also too expensive... and "only" Bialetti" or "Melitta" (V60 at best) might be justifiable) - or (THE BEST ALTERNATIVE FOR ME) "Aeropress".
2) BUT.... Aeropress, Bialetti, Melitta also have their costs, and they are mainly ... (where do you think??) with the coffee itself.
Examples:
a) You take "cheap" coffee (approx. 7,- CHF / kg) - with an espresso machine you should consume about 18g of coffee per double espresso (36-40 ml) (single doses: 9g of coffee for 18-20 ml of espresso will not satisfy you...); so you produce about 55 servings, and per serving it costs you about 12 centimes.
b) You take "reasonably good" coffee (about 20,- CHF / kg) -> you get about 40 centimes per double espresso.
c) You take "very good" coffee (approx. 30,- and more... per kg) -> you get 60 and more centimes per double espresso.
You can calculate your own costs for Aeropress (about 40 grams of coffee powder per 250 ml of coffee - but recipes are very individual and extremely variable with Aeropress...), or for V60 (about 60 grams of powder for 800 ml of coffee; recipes are variable here too).
3) Do not underestimate the investment in a good grinder! (Good hand grinders cost 250,- Fr or more; good electric grinders can easily cost 400,- Fr or more (quickly higher)).
4) The running costs (electricity and water and cleaning agents) I can't quantify exactly... but should be negligible in relation to the coffee costs... (electricity costs are included in the general electricity costs at home, and I don't want to measure electricity consumption... ;-)); I "brew" water myself (because the tap water in Winterthur is quite hard) - costs extremely low; important for me is that the boilers do not corrode (oxidative water) or calcify (lime-hard water); - as references I use kettles that neither calcify nor oxidise with "my water".
5) After 7 months of using my Bianca: (daily operation; private use; 5-6 double espressos per day; daily backflow cleaning with water and brushing of the brew head; weekly backflow cleaning with PuliCaff); no "problems" at all - everything runs like clockwork; - however, I am not afraid of a possible repair, because the Bianca is easy to maintain myself.
6) All parts seem to me to be of high quality; the wooden parts are functional and extremely beautiful (but I would have liked to have tilting valves instead of turning valves [maybe I will do this conversion one day...]).
- But (as you probably see), coffee and espresso are also a bit of a "hobby" for me.... and I think that's a prerequisite... If you "just want a quick coffee", this hobby is "too much of a good thing" ;-)

My machine is now about 1.5 years old. I don't think it has been on the market much longer. So far, I have not discovered any defects. Qualitatively, it makes a good impression, but there are certainly better brands when it comes to workmanship. My skills don't allow me to use the paddle for pressure regulation. That's why I sometimes have to move the paddle back and forth when backwashing, I don't know why, but the pressure builds up faster afterwards.
Maintenance: You should have them decalcified regularly. How often you should do this depends on how often you use the machine and the hardness of the water.
"How much does a coffee cost? ", well, Depends on the price of the bean, the amount of coffee powder, usage and how long it lasts. For me it's about 19g, depending on the bean, for a double. The price range is as high as the beans. Between 20 and 120 centimes for a doppio. Not including purchase (+ grinder!) and maintenance. Everyone has to make this calculation according to their own factors.