With the synthetic fluids out there, GM can eat me if it wants to install reg trans oil thinking I'll be back for another service in half the time. For the extra $40 it's worth it. I can safely assume that a transmission service in Canada will run $250. I can get Amsoil ATF for $10 quart, if that, and do it myself over a couple hours knowing it was in fact changed for 1/3 the price of the stealership.
I got a quote from a Dodge dealer on a 4x4 service (axles and transfer case). They said $542. I purchased the fluids, spend half a day at it (I like to let the RTV sealant dry before I throw in fresh fluid) with taxes, oil and parts, came to ~$130. That was three years ago. No leaks or top ups have been required since.
'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)