Sagna is likely to degrade over the next few years and would have cost us £6-7m to keep for 3+ years plus a sign on of £3-5m. In total, keeping Bac would have been in the realms of £21-26m for a player who is going to get worse over time.
Debuchy is going to cost £9-12m, plus £3.2-4.2 mil a year for 4+ years and a £2-4 m sign on fee. So about £24-£33m for a player who isn't going to be any worse at the end of his deal than he would be today.
It is good deal for the club.
