Oblivion's Wizard's Tower up for 150 MS points
The internet had a collective tantrum following Bethesda's decision to release the horse armor pack and have the audacity to charge 200 Billybucks for it (about $2.50). Pricing the Orrery Map pack at only 150 MS Points seemed like not only a fair price, but a mea culpa on Bethesda's behalf for the horse armor snafu.
The Wizard's Tower download similarly commands 150 MS points (under 2 of your Earth dollars). You get access to the titular wizard's toward, Frostcrag Spire, from where you can teleport to every Mages Guild in Cyrodiil and hone your Alchemy skills in the shiny laboratory. Now we'd like to see the glorified horse blanket take a pricing nose-dive so that the value is more in line with subsequent add-ons.
[Thanks, Paranoised, Tah, and Sjohn]
Update: fixed totally lame error on my part. Thanks, puh_fifer!