I got frustrated with some of the background web sites too. Not only with the way they operate but also the cost involved. Then you have to make your layout conform to their backdrop.
I have used some of the $10 backgrounds found at Nicholas Smith and at Train shows. They are from Realistic Backdrops. I have my own painted sky and clouds, so I just cut away the sky and use the land and or buildings.
I have also found my own backgrounds on the internet and had them printed. You can google panoramic "fill in your scene" like farm, mountains, city, etc. Flickr has great photos that are free to download. Then I print at Wal-Mart, Target, or Nations Photo Lab anywhere from $10-$30 depending on size.
Then I just got a little creative with scene transition by strategically placing items as a view block to try and simulate a reasonable transition.
Here is a scene I had printed. Notice the big barn in the way to break up the 2 photos.
Here is a close up of the farmhouse with corn. JTT scenery real model corn in the front, followed by painted party toothpicks, followed by an internet printed backdrop.
Next is a transition with a strategically placed tree from my printed corn background and one of those $10 Realistic Backgrounds backdrops. Again I cut out the sky in all of them.
Here is a shot with three different backdrops. The two on the left are internet printed. The camera might not do it justice but the color variations appear believable because of the depth of the valley (right) vs the close hills (left). Another strategic tree breaks the scene.
This scene is my computer printed warehouse cardstock and then glued on foamboard. Then more of the $10 Realistic Backgrounds city background. I cut out all of the buildings and rearranged them to best fit the scene.
Just a comparison of the Internet printed scene (left) vs the $10 Realistic Backgrounds (right)
I hope this was value added and gets your creative juices flowing so you can create your own custom backgrounds easy and cheap.
Have Fun!
Ron