Its not a bad idea to do a first drain and fill with something cheap; replacing in 500-5k miles. Supertech has a 75w-140 synthetic that may be a good bet and might actually be nearly the same price as the conventional.
Nope. The SuperTech 75w140 full synthetic is $11.72 while Valvoline's is $12.47, all of 75 cents per quart difference. $3 isn't much savings to fill.
Now on the other hand, SuperTech full synthetic 75w90 is about $5.86/qt vs $9.48 for Valvoline's.
If I went with the SuperTech 75w90 full synthetic instead of 80w90 conventional, then yeah, it's not that much more expensive.