I purchase some parts locally, oil and that I order online (Amsoil oil & filters for my G6). I do an oil change every 1.5 to 2 years depending on how I drive it. I'm lucky to put on 9-10K a year and I service it myself.
For a full synthetic oil change you're looking at over $100 here in Ontario, plus $10 per additional quart. I get the Amsoil fluids and filter for about $60.
My last oil change was slightly more than two years. After 13 months I sucked out an ounce to send in for analysis ($25) and it still had 76% life left in it, hence why I didn't bother changing it out. I also add about a half quart once a year to top up the level between the MIN/MAX mark on the dipstick. Individuals with a brain and change the oil more frequently won't notice any burn off. I can't speak for the 2.4L, but the 3.5L is quite the engine!
Keep in mind too that if you need parts RIGHT NOW, then purchasing parts online isn't the ideal place to get them from, although the 'net can offer much better deals.
'11 Ram SXT 4x4 quad cab - 5.7L V8; 128,200kms
'09 Malibu 2Lt 3.6L - 140,000kms purchased 1 March 2019
'06 Pontiac G6 GT - 3.5L V6; 162,000kms (rear ended 15 Feb 2019, and given totalled title by insurance)