Yarn subbing question

i have someone that wants me to make this: http://www.tinybirdsorganics.com/organicwool/woolpants.html for her toddler and for her baby that’s due in a few months… issue is, we live in upstate NY and these would be for summer time. The yarn suggested (which they sell on their website) is Treliske organic merino wool yarn (sportsweight) and the gauge (size 4 needles) is 24 stitches and 32 rows to 4 inches.

Any ideas of some yarn that I can sub for it? Given how many she wants and their limited income I’m looking for fairly cheap yet decent quality.


on the link they mention wool-ease that you get two balls of wool for $5, somebody have made these out of acrylic which also worked well. Sorry don’t really know the yarns over there, except for Caron simply soft which is acrylic and cheap. maybe some sort of cotton blend for the summer.