The second I walk in to one of them I make a list of all the things I want to fix or upgrade and spend the whole trip either hiking or at the hardware store.

Besides storing in a savings account, I was thinking something like a certificate of deposit set to the lease term.

If you don't mind a couple dings and blemishes, I've had good luck with the "damaged" appliance section of stores like Lowes or other such places.

Since you already donate to the community, perhaps you could morph that donation into a social media contest.

Stock shelves in the grocery store, work at Home Depot or get your own side gig mowing lawns, or fixing something you know how to fix or whatever. 

The other thing we like is that being web based, we can all easily see everything at any time, such as 'what kind of stove is that we put in at such and such address when we are looking for parts at the store etc....Dan Dietz

I have a discounted building supply store In my area.

All paint stores should be able to provide them for you for any chemical or paint they sell you.  

Keep in mind that with the big box stores, manufacturers often just give their product a different name.Curious, doesn't your contractor have supplier relationships from which they would use to source the material?

They know every painter that comes in there to shop and can makes recommendations.Also,try the local paint stores like Sherman Williams and others to see which painters shop there.I bet the salesman have family members who are painters or know who the best painters are around there.