I saw this site mentioned on another forum:
Discount Dance. I thought that the women on this site might appreciate the information.
Even though this site specializes in ballet atttire, the poster suggested that some of the outfits could serve as inexpensive costumes for Syllabus-level competitors.
Item N8367 was mentioned as suitable for Standard and Smooth (with some embellishments,I guess). Items 7825 and N8378 were listed as options for Latin/Rhythmic outfits.
Knowing how much the ladies like to dress up, I imagine that many would find these costumes too plain or simple. However, for someone starting out (Who else would be doing Syllabus?), they could provide some inexpensive alternatives for those first couple of years of competition.

jj