Since Sony introduced the new A200 at CES and the A300/A350 at PMA, prices on eBay for used Minolta lenses have increased significantly.
The 35/2.0 used to go for about $400; the last three went for over $600!
The 100/2.0 used to go for about $700; the last two went for $1,000 or more!
Even the 100/2.8, which used to go for about $400 is now going for about the price of a new Sony 100/2.8.
Sony needs to re-release some of those old lenses just to keep the prices sensible.