You are definitely thinking outside the box.
Some things to consider, though:
Lowe is getting $9M, $9.5M, and $10M the next three years. Harden ($1M, $2M, $4.5M), Haren ($0.7M, $2.2M, $4M), and Blanton ($0.35M, $0.35, 1st year arbitration) over the next three years. All three of those pitchers are, if not better, just as good as D-Lowe, but at a much cheaper price.
Zito makes $8.5M and Wells, once the incentives kick in, will make $9M (assuming he makes the required starts/innings). The A's will lose either of those pitchers after the 2006 season. Wells will go due to retirement, while Zito will go via FA. The catch is that Oakland will get compensation picks for losing a FA, but would get nothing for losing a retiring player. Being on a budget, and having a history of good drafts, makes it clear which is the better option for Beane.
Loaiza has been signed for $7M per over the next three years. That gives them Zito, Harden, Haren, Blanton, Loaiza (5 starters) at $17.55M in 2006 vs. Wells, Harden, Haren, Blanton, Loaiza, Lowe (6 starters) at $27.05M. I can't see them paying an extra $10M for a 6th starter on their budget, especially if it means that they will lose the extra draft picks that Zito signing elsewhere will grant them.