OK, so help me out here.

I have always attempted to accrue DL Skymiles to use for awards on South African Airways (between US and SA).

80,000 Skymiles for a coach ticket on SAA
120,000 Skymiles for a business class ticket on SAA

Approx. prices I have encountered for these same tickets (paying cash)
$1,000 for coach
$6,000 for business class

Using everyone's math
$1,000 / 80,000 = 1.25 cents per mile (not too great)
$6,000 / 120,000 = 5.00 cents per mile (very good, the higher cents per mile the better)

Now, I am faced with the following dilemma
Trip to Europe - DL Skymiles 50,000 coach, 90,000 business
Cost - About $700 coach, $3,800 business (just quick Orbitz price checks)
700 / 50,000 = 1.4 cents per mile
3,800 / 90,000 = 4.22 cents per mile

Perhaps answering my dilemma, I should pay cash for the coach ticket But, if I want to go business, I would be wise to use miles. The higher cents per mile, the better.

Right?