It is much cheaper to purchase silk/fabric plants at craft stores or walmart than it is to purchase fabric plants at the pet store. If you use the craft store plants, you can take them apart, take out any metal in the leaves (middle stems are okay, but make certain that no part of the metal is exposed to the water (seal with aquarium sealant)), same with sealant to glue them back together again. :) Then you can use some additional aquarium sealant to apply polished stones (also at craft stores) to the bottom to weigh them down in your substrate.
With a sorority, the lower decorations are not as important as having enough plants in all three levels of the tank, bottom, middle, and up near the surface. My guys *love* having several floating plastic cups (short, squat, plastic tumblers, you can usually get them in a set of three or four at walmart, grocery stores, and dollar stores) around the top as well to give them additional places to hide out. :)
Doing it this way, you can spend about ten bucks, and have lots of plants of all different heights, and plenty of floating caves for them as well. :)
I hope that helps, if you need more information, PM me. :)