I'd much rather we rejected any bid and activated the buyout clause for the following summer to be honest. By next summer he'll be 30, still a good age for a CB but not young enough for a club wanting to spend mega dough on, £25m even in the inflated market would be pretty high for someone of that age and he won't get say a 3-4 year contract on £150k+ a week by then, in that time maybe we could convince him to commit his future.
As has been pointed out, we've done well in his absence thanks to Dave Sanchez's arrival and the likes of Foyth and Carter-Vickers both seem destined for big futures but it doesn't take away the fact that Toby is better than any CB in the division and therefore losing him would be hard to take and definitely weaken us.
If he does go, I'd rather it be to PSG, they've been linked with him along with Utd, Barca and Real. We've struck up what seems to be a 'friendship' with them, they bought Stambouli off us a couple seasons back and we've taken Aurier and Moura this season while we've also been linked with summer moves for Kurzawa and Pastore, so if Toby was dead set on leaving I'd rather we looked at trying to do a deal that got us one or both of those in return.