Cost of Equal Sweetener

I dawned on me the other day that I was spending $86 per year on 2 boxes of Equal sweetener - a total of 1000 packets.  How ridiculous is that?  We have a membership to Costco and the only thing we buy there is the 500 count boxes of Equal.  We typically go through2 boxes in a year period.  So, if you add in the cost of the membership with what we pay for the Equal, I am spending $86 a year on sweetener.  If I buy that same quantity at the local grocery store, it costs me about $15-$20.  I don't see myself renewing that membership anymore.