If that's what it costs to keep them safe from the drop zone and challenging for a Euro spot, so be it. That's the price they're willing to pay. I don't think they're idiots if they now this player is going to add value to their squad. Plus he's coming from a CL winning team. They can't offer the market value and expect to get him.
If there are players out there that we know will really improve the team and unit by quite a distance, we need to really up our game to secure those players. Market value shouldn't come into it. If Wenger is saying there isn't anyone out there of that quality, then someone needs to question his judgement.