I think we are getting ripped off and I expect it will get worse as the 'staycation' becomes a buzzword for the great-unwashed.
If I used more than I do I might complain a little more but my current bottle is now 1/4 full after 2 years! Tea and pasta!
When you exchanged your bottle
@Phil_G what condition was the bottle in?
Is there anywhere (except the likes of GoOutdoors, camping shops etc) that refill the container you take to them? The number of times I've been to look at various exchange sites and the replacement 907's have been rusty crappy things you wouldn't want to have inside the van.