It may be a bit cheaper... but takes a LOT of time.
I made the decision to DIY so that I could get what I wanted... none of the pre-made ones had everything I desired. Mine has a regular ladder, a spiral ladder, a swing, a cargo net, a training perch, lots of toy haners, climbing chains, and their Hoopball or a boing can go in the middle. Up top, there are food and water cups and a toy/foraging basket for the foot toys they adore.
Mine is here in unfinished state:
Robyn's playgym... a work in progress - BirdBoard.Com - Parrot Message Board & Pet Bird Owner Forums
I need to post pics of the thing done!