That's just your opinion, not everyone mines to sell for BTC. Maybe some people like to mine different Scrypt coins.
But yes for some people it's better to buy low and sell high.
But I rather buy a miner that I know will have some resell value left when I'm done mining, than try to out smart the market.
Remember that the ASICMiner USB miners still sell on eBay.
Because you can allways find some idiot...
With 10% Difficulty increase, you get approx 20$ worth of coins with 1 gridseed miner @ 350KH/s.
After that 120 days, mining won't be profitable.
Paying 200$ for such a miner is just a waste of money.
You could buy 10x the amount of any Scrypt Coin NOW.
If the price goes up -> you gain 10x more than with a miner. Selling ASICs is most profitable for the sellers.
That's why you just point your gridseed miner at a multipool, which is always switching between the most profitable coins . . . .
Also, the keyword you used is
if. If the price doesn't go up, you're out your money. With a gridseed miner, using only 7kw/h is more cost effective than mining with a gpu. Many people have bought coins from exchanges only to see the coin die or drop 50% in value. At least with owning a gridseed miner, you still have the hardware to continually mine other coins at low cost so long as scrypt coins are still out there.
Also, as long as you mine the right coins at the right time and sell at the right time, you'll make you for the cost of the miner plus some.
And again, Im sure a lot of people using asic miners are joining multipools to recoup their costs quickly. IPOminer has brought in good profits just by mining, holding, and automatically switching coins to hold and sell later.