At soon as you have an employment you will have to pay a bit up to about 800€ for higher salary levels for public health insurance - half of which you never see in any calculation, payed silently by the employer and the other half reduced from your pay check.
Additionally you pay mandatory retirement insurance, loss of work insurance and old age care taking insurance plus tax. (not sure about translations)
So from 7500€ a month you will end up with about 4900€ after all this, if you are married otherwise you pay a bit more tax. If you cannot find work and cannot pay you have all the same benefits, except the retirement will be minimal.
To sum up have social security with this. Every treatment is payed (sometimes you have to pay a little in top, let's say you want plastic instead of metal teeth fixes, basically for everything not mandatory in the eyes of the doctor you have do pay the difference).
But mandatory stuff is completely covered, up to brain tumor removal with the particle accelerator in Heidelberg or so.
Some fine print:
If you and your wife work both pay for family insurance (so up to 1600 together if both earn very well). If one works alone and pays there is only one payment.
Actually you can opt out op the public health insurance as soon as you reach the maximum. Then you can opt for a private insurance.
To sum up again: with all this Germany is certainly not the place to become filthy rich by saving money from your income as employee. But for about third of your salary you get a a) good infrastructure (tax), b) mediocre but ok, bancruptcy protected retirement, 3) no need to fear health issues from financial side, d) job loss insurance for a year (pays on about 60% after that social security... much less like a flat for the family and 500€) and e) care of a certain degree when of old age.
Quite a good deal for me. Still it's better to save also several 100k for retirement. To become rich here you need to start a business, be very creative or become a top manager or politican like everywhere else.
P.S. 5AM here sorry for bad grammar, typos and information gaps =)