We have a whole collection system based on 1000 litre black barrels. The rainwater is collected from various roofs around the farm and collected in the big barrels, then directed, mostly by gravity, to drinkers for the sheep, and by both gravity and an electric pump to the veg garden and polytunnel. We don't have mains water, and our well is ancient (we think it dates back to the 1500s at least) so can run dry, which is why we use it only for domestic water. I love the gravity system as water can be made to flow uphill a bit
These barrels used to cost about £100 back when we set up the system, but I think they are much more than that now - they are former bulk orange juice containers.
The bath water is only for emergencies, but where we live now we don't have a bath and we haven't worked out how to collect from a ground level shower.
Modified to add:
I had a look on google and cannot find the type of barrel we have. They all seem to be cuboid white plastic with a metal cage around and are much cheaper than what we have. The drawback of clear or white water collection containers is that algae build up quickly in the water.