The are probably other vendors, I only know of this one:
Arrow Star Discount Inc.
3-1 Park Plaza, Dept. 9, Glen Head, NY 11545
1-800-645-2833
What I've ordered is :
ABF1030 Pack of 6 White All Plastic Chain Link Posts
ABF1027Y Fifty feet Yellow/Black Plastic Chain Link
Total price was 200 and change. They might question you (or purchasing)
concerning color combination, but for NMR lab, I think the above is
appropriate (IMHO) :-) (white plastic chain doesn't look off-limits
for me at all...)
You might want to get a couple of bags of sand gravel or concrete
(rebar & BB's are out, right? :-)) to weigh down the bases, although
I haven't found a need for that in my situation.