Looking at the Blue Jays this offseason, I don't think they get that huge of a bump in payroll where they're able to go out and sign big names like Garza, McCann, Santana, Tanaka etc like many people on here are thinking. I don't think during AA's tenure we've seen him sign a big name free agent. That could be a repeating trend this offseason again.
AA likely will try and acquire a starter through trade, and I think Cahill fits the bill in terms of the Jays strategy this offseason. Cahill is still young, under club control (possibly until 2018 with the options) and gives the Jays a durable arm that could provide 200 quality innings, which is what AA has stated numerous times he is looking for. Obviously, Cahill isn't a No. 1 or 2 starter by any stretch of the imagination, though he can settle in as a dependable middle of the rotation starter. His BB rates and low K totals are worrisome, though he is a ground ball pitcher so the Jays better have solid defense behind him. In terms of the price, the Jays can likely trade some BP arms and a C level prospect for Cahill which wouldn't be that much, especially considering the Jays are trading from an area of strength which is their bullpen.
I just don't see the Jays in on Tanaka, or Garza since that would be likely out of their price range. I wouldn't mind Lincecum or Ubaldo though I doubt the Jays sign them. As for acquiring an ace through trade, I doubt they have the pieces to land a David Price or Chris Sale, and I doubt the Phillies move Lee and have a fire sale just yet. In terms of the asking price, contract, and type of pitcher, I think Cahill is the type of pitcher AA is targeting (someone who is durable and could give the Jays 200 innings). Some people on here even suggested signing Bartolo Colon to a one-year deal which wouldn't be that bad as well, and is something the Jays would still be able to do even if they traded for Cahill.
Possible rotation:
Dickey
Buehrle
Cahill
Morrow
FA signing like Colon or Hutch/Happ/Redmond/Drabek etc.