When it comes down to it, Boyds is a business. They have to make money! They already have a reputation, so putting money into tooling to make stocks is no longer an investment.. Now they are at the point where they have to cover all the costs to make the stock, or its just not worth doing at all. Their stocks are fantastic, and they have a huge reputation in the go-bang side of shooting, especially competition. If you go to a national or even high regional long range shoot, I bet 75% of people there have boyds stocks.
Normal stocks are in the 150 range, with the high end obviously costing more... thats not a lot of profit at the end to justify throwing $15,000 up front to design the tools and programs needed to make these stocks on their machines. I cant imagine you would ever get enough owners to make it worth it, they probably need a couple thousand orders. I wish it was cheaper and possible though, theres a lot of air guns that would benefit from having a high quality stock... plus they sure are lookers.
The avenger is only popular because its cheap. Up the price by $200 and I dont think anyone would even be talking about this gun. I'm guessing thats why air venturi wasnt interested in a partnership, they understand that the gun is a budget gun.. and as soon as another company does it better for the same price range, their sales hype is over. Look at the umarex gauntlet, just two years ago they were the MUST HAVE for budget gun. Now they discontinued the 177 and raised the price on the 22/25 and nobody even talks about them anymore.
Look for the budget gun market to be flooded with new guns in 1.5-2 years, with the companies seeing how well the avenger went over... with even experienced shooters buying one "just to see what its all about" because of the low price and good features. Someone will find a way to get a LW barrel in there or get it into a bullpup design or something like that which will fuel this craze all over again.
Point of my last couple ramblings there, is that there is not a likelyhood of long term attraction to the avenger so it would not be good business for Boyds to up front the costs to make stocks for it. Is not a remington 700, or savage 110, or marlin 60 where the gun will be around for another 50 years so plenty of time to sell stocks.