Pauline,
You should go by DAZ3D right now, they are giving away Bryce 5.5 and Hexigon 2 both of which can be used to design props and to some extent more advanced terrain. I don't know if I am special in that I got Bryce 7 pro free but I have purchased it in the past. as of Sunday they were still giving away Studio 4.5 Pro as well. And if you like wasting tons of time to learn Studio, that is a bargain. I am using both Poser 9 and DAZ Studio 4.5 Pro. I am still trying to get used to different ways DAZ maniputlation is accomplished and for me its far from simple. I have though been a Poser person from early on in the Poser 3 era so I understand it well. On the good side both programs have their advantages and disadvantages but they both have plenty of tutorials that can help you improve your learning curve. If you are an OLD dog like me you like to learn by trial and error because you think that you can figure it out if it's intuitive, well that doesn't work well in this age. Save yourself some time and watch the tutorials.