Dollar Stores are a Scam
I think the topic is on point but Dollarama seems to have monopoly and they often go direct to the manufactoruer to get a good deal for the end user. Make sure you do a cents per gram comparison to assure you're actually getting a deal and you're good to go.
Personally I can buy a $1.49 hose adapter that sells for $4.99 at crappy tire and they seem to last longer as well.