Rainbow playsystems are great for older kids (4-10+).
We were looking at a $5K set and had serious heartburn over the cost. We put an add in our local paper and found someone with a 4 year old $5K set (the same one we wanted) that they were looking to get rid of it. They wanted $1K.
The catch being that it needed to be moved from their yard. Well, I'd say it was a fun job that my father and I did but that really depends on your definition of fun. Rainbow sets are expensive because they are heavy and built well. We moved it into our yard within 4 hours and set it back up within 3 hours. It was a lot of hard work and heavy lifting (the deck was really fucking heavy) but it was worth it.
We refurbished the ropes and bars, and I restained the entire system with Rainbow stain.
For $1K plus a lot of sweat equity, we now have a $5K Rainbow system.
I'd recommend this route as I see lots of people who are done with their systems and are looking to get them off of their lawns.
BTW, we have a three swing set. Three adults can swing full tilt on this set without upsetting the structure. That is why you spend the money on a Rainbow. When kids (10+) swing the playset does not jump. It's perfectly stable.
Corey