Any model terrain supply deals

[PJ]

Are the supplies specific to DnD or is it just raw materials that you use to make things for DnD?  Do you have any links to the types of things you are looking for?

Things like this Doors and windows templates, Different types of flocking, or Texture rolling pins (just a few for example). It doesn't need to be specific to DnD, even silicone molds would be nice to find at a cheap price. I like crafting as well as woodworking and it's nice to make stuff up sell especially when work gets slow. I've been watching some different YouTube channels that make stuff for tabletop gaming (wargaming, DnD, etc) as well as making Halloween props.

It looks kind of similar to the stuff people do with model trains.  When they build like a city around the track, I wonder if any stores sell things marketing to those people but would also be useful for you?

May be a really bad idea but for like the floor tiles I see people make can you use expanding foam in a mold?

Amazon has a craft section for promo codes but it only has 3 codes in it right now and they are all for colored markers.

Have you ever tried going to Michaels?  They usually (corona might have this changed for now) have a 40% off single item coupon in their sales flyers.

I've been to Michael's, Hobby Lobby, Dollar Tree, Joanne's, Dollar General and Family Dollar. Hobby Lobby and Dollar Tree are by far the cheapest. Michael's is too expensive. Joanne's has an app with lots of coupons in it for online only and in store. 
A model train store would have more inventory to look at but there's not one close by.
I use pink insulation foam, foam core (the foam boards from dollar tree), wood and only recently giving my hand at air dry clay (it's sitting in a mold right now drying).
I've been told that flocking is just saw dust with food coloring added, since I do wood working as well, I'll have to test that.
Included pic is just a glimpse of the "art and crafts" area of my new shop. Messy at the moment but will organize it soon.
*edit* I chose a file to add but it's not showing up, I might have done it wrong...

After choosing the file did you click the "Add Attachment" button on the right side?  I think the picture size limit is set to 500kb or something so that could potentially cause a problem.