2 CPM!?!?! Wow, that is very low in my opinion. I am a huge fan of getting the *most* out of my miles. I look for a minimum of 6 CPM. Mind you this figure is dependent on what FF program you are in. I'm an AC guy myself and redemptions are pretty good, but for instance Delta is terrible for CPM (but you get a lot of bonus miles with Elite Status) and Cathay isn't as good as AC, but is still decent.

Don't even look at economy class tickets. Usually it's twice as many points (some exceptions) to fly business but 3-5 times more expensive in cash. So always save points for business class (or first if available).

$1400/$6200/$10500 60K/120K/180K Return Econ/Biz/First to Asia CX 2.3/5.2/5.8 CPM
$1500/$9500 75K/100K Return Econ/Biz to Asia AC 2.0/9.5 CPM
$1200/$7500 or 120K/240K Return Econ/Biz to Asia DL 1.0/3.1 CPM

Now I'm making the assumption that we believe that the products in question are worth what they are asking. For me personally I would probably go on CX if I were paying because I don't feel the difference in products is worth $3000. BUT if I were using miles and had the choice I would pick AC, 1 because I like the product and 2 because I am getting a great CPM! (3 Also to note is Cathay as one-way award options and Air Canada in effect does not (they do but CPM is very bad) so the other reason I would burn AC points on a round trip is because I would rather save CX points for a one way award when I need it)

Europe is similar-ish. With Economy fares sometimes lower (and hence lower CPM).

BUT there are some cool exceptions, but you have to know the rules.

For instance, you can really mess with the routing on award travel using partner airlines. For AC, you are allowed 2 stop-overs and 1 turn around.

I recently booked: YEG->FRA->BKK->SYD->YEG for 100K points in business (it's a return to Australia with 2 stop overs). The cheapest way of doing this itinerary would be a Star Alliance RTW at about $10,000 so that works out to 10 CPM!

Also don't discount buying miles. With Cathay you can buy miles up to 30% of the miles you need as long as those miles aren't in your account (in lots of 2000 miles for 60 USD or 65 CAD). I have a credit card that transfers points to Asia miles, so I will transfer miles needed x 70% and buy the rest of the miles. Because my redemption is at 5.2 CPM and I'm buying miles at 3.3 CPM (prices above are in CAD) well I'm making 1.9 CPM on that 30%.

Even if I had no money, I would rather pay for an Economy ticket on credit card and save miles for a business class award. At 20% interest, over 1 year $1500 becomes $1800. On AC $1800/75000 = 2.4 CPM. Not good enough for me by a long shot!

So the things to note:

1. Always fly business or first when spending points.
2. Know the routing rules and make the most out of them.
3. Buy miles when you can.

Happy Hunting!

NOTE:
You have to take into consideration that paid business fare usually has much more flexibility when it comes to choosing and changing dates. So if you are flexible for choosing your dates of travel and know that you wont be changing the dates, than this is a fair calculation. But there is obviously value added to the benefit of access to more seats and flexibility that isn't accounted for by simple dividing the price of the ticket by the amount of miles burned. I've paid for a business class ticket even when I had enough miles because I knew that my dates weren't set and I might have to extend my trip or change dates or what not.