Independent IT contractors in Germany don't have to put any money in a retirement fund, but hopefully they do, plus they pay 100% of their own health insurance, IT equipment (sometimes), insurance for their business (occasionally required)... A contractor making 10,000 a month is not comparable to an employee making 120,000 a year, probably closer to 90,000? I didn't mean to imply that it's a lightweight model, it just shifts the burden to the contractor.
Thankfully 80 EUR/h is not the upper limit if you can cut out the middleman. Speaking of which, I've heard third-hand horror stories of Polish SAP contractors where the middleman(!) made 65 EUR/h, which was probably more than half of the client paid - ouch.