I have a few online stores I use regularly to buy various items for QFPS: Hardware from McMaster-Carr, computer parts from Newegg, used equipment from ebay, etc. The one I tend to use the most for small components of all sorts is Digikey. They have an enormous selection, good shipping choices, and they don’t care if you need just need one LED or 10,000.
A few days ago I ordered some connectors and wires to make a cable harness for one of the Quality Firmware projects, and to make it look good I also ordered some heat shrink tubing, at under $1 for a 4 foot length you can’t go wrong. Then the box showed up ….
They had used a 4 foot box to send my 4 foot heat shrink tubing!
To their credit, it actually says on the bag containing the heat shrink tubing “Do not bend”. Next time I order some, I will make a note like “it’s ok to bend the tubing”, so the box has a chance of fitting inside the mailbox ….