Here is the recipe per Finskis post here:http://forum.beemaster.com/index.php/topic,34944.20.html
mix 100g sugar + 100 g water + 7,5 g oxalic acid.
This enough for 3 two box hives or 5 one box hives.
Cost is almost nothing.
Most inexpensive small kitchen scales measure grams and ounces.Don't overcomplicate it!