I’ve just finished my Rohloff oil which I bought as part of a forum group purchase Many years back when only litre sizes were available. Given that I’ll likely be still riding the hub in another 14 years, I’d best get some more ordered.
I'm just finishing my split litre from about the same time, I kept 500ml, I've used more flushing fluid than gear oil, so that's gone first.
In the intervening years, Rohloff seem to have caught on to people splitting what were sold as workshop tins, and now sell in 250ml quantities, cleverly priced to be substantially dearer per ml than the big bottles, but not quite substantial enough to bother with the hassle of splitting... The new oil looks considerably different to the grey stuff we've been using, though the SJS photos show different oils depending on the quantity, I have no doubt that whatever they're selling will be fine. I haven't decided which quantity to buy yet, my Rohloff collection has grown to three, but I can't imagine I'll be doing the same mileage in another 15 years.
I'm tempted to start using the method in the "Living with a Rohloff" brochure - double flush, add 25ml oil, mix, drain most of it out again. But that obviously uses twice as much flush as oil and I haven't seen them sold other than together(Though I haven't looked hard) I'm also tempted to do them all every January, maybe the same weekend, save having to remember which is due when, though the most used bike might need an extra one mid year.