Had a look at what Skethup Pro can do on YouTube.
I'd have little interest in the PC World type of package.
Seem to think we all live in US utopo-suburbia, giving us what they think is
good enough for people like us.
It looks like the main expense here is the cost of making suitable landscaping
objects that are vivid enough and plausible (i.e. not all the same size/shape,
not growing alongside other species in an unlikely way for adjacent growth)
in the eye of an experienced person.
But thanks to everyone for your suggestions.