As has been said, it all depends on your material costs. Around here, it's tough to get any varietals other than clover & alfalfa, and those aren't exactly cheap. Anything more "exotic," like orange blossom would have to be shipped quite a ways, which in most cases, will nearly double the cost, which negates any & all savings from buying in bulk.
Such circumstances actually make 1 gallon batches more affordable for me, even though I may actually be paying a higher price for the varietal honey, I'm paying for a smaller amount and hence, less shipping. So if I make a batch with local wildflower honey, it'll cost me about $6.50; if I make a batch with pure acacia honey, it'll cost me about $24.00. Big difference, but that's what I have to work with.
Regards, GF.