I had a look at IG's platform today for both spreads and CFDs and the Apple spread is approximately 16 - 20c on the spreads and almost the same on the CFD account. Apple has been very active post its Q4 announcement, and I tend to notice that when there is lots of volume in the underlying market and hence lots of activity, the spreads can narrow quite a bit.
With spreads, the cost of trading is in the spread (+overnight financing), with CFDs you pay a % eg. 2bps when buying + 2bps when selling, with a minimum amount being US$15 with somebody like IG, so US$30 round trip so to speak.