I assume everyone knows of Jerry's, Blix, A&C, et al, but have you found the Jerry's wholesale division?https://www.aswexpress.com
You have to join, but I have saved so much money on canvas, stretcher bars, etc, that it's been worth the $99 membership fee. Linen, especially, if fantastically priced!!
I have not tried their pre-stretched canvasses - but the prices are great.
I have found a slight problem with their stretcher bars - they don't match up with the ones I already have (from a variety of sources) - so I can only use them with themselves.
(these are the "pro-light" - it appears that the heavy duty ones are cut like, i.e., the Masterpiece bars).
And a box of decent brushes for under $1/e (166 brushes) - these are probably made in China, and are both in bristle & faux bristle. Since I am a "brush killer" these have been absolutely perfect. (Also trade them for art lessons
I have not tried shipping to Europe - I purchase & pick up on my visits to the US>
Check them out!
By the way, Jerry's was having a super sale on another manufacturer's paint (Michael Harding) and Blix matched it to the penny. Go figure.
Of course, I don't use other manufacturers' paints (except when they have a cool colour that I want to use for experiments....
I also found some inexpensive and useful stretcher bars at https://www.wholesaleartsframes.com/standard-bars-3-4-inch-deep/
- their canvas is nice & well priced. The bars are a little inconsistent in quality, but for the price? Good deal. Fine for the smaller pictures - not set up for a cross brace. (Although, it appears the larger one might be.) I find them fine for cotton canvas, but I worry they are not heavy enough for that tough pre-primed linen.
I hope this is helpful to people - post your "finds", too, please!