about 30 mins and 7.75% tax
That puts the price at about $300 after tax and gas (assuming 2 gallons - YMMV).
This chip could be as low $160.68 (depending on 7% cash back from one site and 5% cash back from Discover) including shipping. Without cash back, it's $182.28.
If you can get the board online for $120 or so, it's break even without you leaving the house. If you cannot find that board for that price and want it, you would be best served to drive to MC and get the combo.
Engineer: Always FREE after rebate!