Excuse me while I mince words. What do I mean by an indirect direct model? I'm glad you didn't ask. I am going to tell you anyway.
If you read my musings regarding the subject you know that I don't believe that a true direct model would work. I.e. Topps produces 50 El Grande Pujols patch cards and sold each on their website either through first come first serve or auction based sales model.
I think its possible that something might work that is similar. We know that Topps Sterling is a huge, huge gamble. 200+ Washintonians buys you a box with a "mystery" pack, a hit, and four serially numbered "base" cards. The problem is that while you have a long shot to get a Ruth jersey card, you might end up with a Mattingly /10 that signifies 191 GDP or 191 career grounded into double play. The outer box contains an inner box. The inner box tells you the player, but that's it. You can often find sealed inner boxes for sale. The person has opened a case looking for the big hit player and is trying to sell off the others to minimize the loss.
I avoid products like this like the plague. Too much of a gamble, the lesser hits and even some of the "major" hits don't come close to supporting the cost of the box. But I may have a solution.
You know how topps lists the A, B, C, D so on and so forth levels of autos? The A's have long odds, the D's are pretty much going to be in most boxes. What if Topps offered sealed boxes direct or indirect that told you what group the auto or patch was going to come from? Topps could split those levels into sub levels of retired, active, and HOF. That way the "chase" is still intact, but you know your not going to get totally jobbed on a box. You might not pull a Ripken Patch/auto, but you might get a Gwynn patch/auto. A level boxes might bring $300, B level $200, and on down the line. D level boxes are commons and would sell in the $40-$60 range. These could be sold in high end or base level products.
A box of base cards at $300 you ask? Well the price would have to be worked out and I am using that as an example, but there are many set collectors that might decide they want to get a big auto or patch card and collect the set too. In addition, the "high end" might get you two hits and no base cards. This would cut down on the crappy hit a pack model that upper deck uses in SPX, it might not.