I liked Tejada, as a player. I would have been happy to see him at 3B, although he is far from a certainty to play 3B well.
But I don't assume the Astros could have signed him for 6mil/1yr. Baltimore most likely stumbled into that deal as all accounts indicated Tejada wanted more money and years from Houston. The fact that he settled for less money/years is very likely a result of Houston moving on, along with St Louis for that matter, leaving him few options and a weaker position for a contract. Asking X, or Best Offer... that's all it boils down to.
eta: Oh, and the 1.6mil difference between Feliz and Tejada, that just bought Houston that critical lefty specialist. I don't care what equation you use, two Major League players for the price of 1, that's a win-win.