I do similar bi-weekly water changes on both my 55g saltwater and 120g oscar tank. The only extra time for my saltwater tank is that I remove the powerheads and clean the main pump on my saltwater tank more frequently because I am more concerned about peak water flow in that tank. In addition, I have to add about 1/2 gallon of makeup water to my sw
tank every day. This becomes an issue on vacation because I don't do auto-topoff, which is annoying over the "set it and forget it" aspect of my oscar tank, but other than that they are comparable.
, the startup of a saltwater tank is what consumes most of the time and money. There is much more frequent testing (speaking of reef tanks) involved to achieve various balances, etc. To be honest though, I "tweak" a lot in my tanks rearranging, propagating corals, etc. but that is because I want to. If you can appreciate the time in the first 6 months it may take (extra water changes, etc.) I don't think you will be disappointed.