Upgrade S60 tempomate unit!

Moin! In the meantime, I found out here in the forum that you can install the cruise control unit for the S60 yourself. Then you would actually only have to pay the costs for the hardware (“Lenkradtasten” for approx. 30-50.-Euro and certainly the software update via the Volvo-VADIS system! Here in the forum was called a price of 250.- Euro! Is that so? Does someone have experiences with above mentioned topic or other useful information? MfG Th.