ItStays generally costs more if you buy it from a wig company/vendor. Check out local medical supply stores where it is sold as a body adhesive (often for surgical stockings/compression socks) to see if you can get it there for up to half the price…it’s the same thing!
In Canada, try this site…they won’t sell to you direct, however it will help you to find a dealer in your area:
Note: the U.S. website that I mentioned is only one that I found in a quick online search using both “ItStays” and “body adhesive” as key words…I can’t recommend the site as I haven’t ordered anything from them. Please do your own research/due diligence if you want to purchase online from any medical/surgical supply company.