Agreed - Lego is not going to risk their reputation based to make a relatively small amount of money. Another release of 20,000 @ $200 would gross $4M. This from a company that made a profit of over $1B? No way.
Let's try to put some more numbers to the discussion:
Total sets - 20,000
Estimated # of sets released before yesterday's next wave: 10,000
Total sold on eBay, September: 421
Total sold on eBay, August: 388
Total sold on Bricklink: 208
Total sold eBay/Bricklink: 1,017
This doesn't account for Craigslist or Kijiji sales, but I wouldn't put these at any meaningful volume. I have seen anecdotally that Chicago's CL may have sold 1 or 2 since its release, so perhaps we can conservatively assume 83 sold on CL/K/other outlets to even out a grand total of 1,100 flips, or 11% of the total current sales.
You mentioned that eBay and BL shows roughly 250 sets currently for sale. That brings the total flipper quantity to 1,350 sets, still only 13.5% of quantity sold.
To me, that's not a lot. If Lego has only released 5,000 to date, the total flip purchase % increases to 27%. This is not an inconsequential number, but still not an overwhelming majority. If they've released 15,000 already, you're only looking at 6.75% of total current sales, an even less significant number.
My guess is the overwhelming majority of these have gone to Technic fans that knew they would have to jump on this set fast in order to ensure they didn't have to pay way above retail for a once-in-a-lifetime Technic set. My guess is that most of the "unflipped" sets etiher have been or will be opened.
I would guess that once it goes officially EOL on Lego.com, you will see the price begin to creep up further, but as Ed said there are some potential caps on Technic sets. First, while a popular theme, Technic has never been a "blow the doors off" theme, and the post-retirement market for Technic sets isn't nearly the same size as the Star Wars/UCS market (as an example). That will likely cap returns. Also, Power Function sets can be intimidating to a group of Lego fans, so again your market will be smaller still.
I'll leave you with this thought: if yesterday's wave is the last release of the 20,000 (let's say 15,000 had been released previously and 5,000 are being released now), and we extrapolate the current numbers with current percentages, you're looking at a total "flip" quantity of 1,800 of the 20,000 released. That means 18,200 are either being held for "investment" or opened. While some of the 1,800 will also be sold for investment, we're still talking about a fairly small percentage of the 20,000 total.