I doubt he's going for anything near £30 million unless there's a bidding war, and who's going to get involved? Most other clubs either don't need him, are focused on retaining the players they've already got, or have been hit by transfer bans.
Walcott was slowing down when we sold him, but he had a higher profile than Fraser, and he went for £22 million according to most rumours. I think that's where Fraser'll land. It doesn't prevent us from looking at bigger targets in addition to him, and we can get most of that back in a year or two even if he flops.
Biggest issue with a Chambers swap deal might be that they feel they'd rather have cash to spend on someone who can replace Fraser's goals and assist in the team.