I recently had to remove a lot of coins from cardboard 2x2s and put them in new 2x2s, so I've been in the market for lots of new 2x2s as well as some new pages to put the 2x2s in.
I've purchased supplies from two sources - a local dealer and BCW supplies online.
First, the dealer:

Cardboard 2x2s - Come in a 100 count (not storage) box, Armored Brand USA, $4.95/box. No surprises, exactly what you think they are and should be. Tested negative for halides using the Beilstein test.

20 pocket pages - Lead Dog, $.75/page. I didn't like the look (or smell, or cost) of these pages, and no surprise, they
tested positive for the halides with the Beilstein test.
Second, BCW supplies:

20 pocket pages - I bought a box of 100 for $21.50. They're advertised as acid free, PVC free and made out of polypropylene, they also tested negative with the Beilstein test.

Cardboard 2x2s (quarter dollar) - Come in a 100 count, with a storage box, $5.95/box (without the box is $4.00). No surprises, exactly what you think they are and should be. Tested negative for halides using the Beilstein test.

Cardboard 2x2s (half dollar) - Come in a 100 count, with a storage box, $5.95/box (without the box is $4.00).
Two surprises - First, these are notably
thinner than the quarter dollar size. It took 22 of these to reach .5 inches measured with calipers vs the 17 it took with the quarter dollar size. Second, there is an
embossed BCW logo on both sides. The logo is oriented so the letters appear right side up when the closed side of the 2x2 is on the down side.
Final thoughts:
I don't like the embossed logo on the BCW 2x2, although some may like it. It wouldn't be so bad if it were on one side only. I also don't like the (lack of) thickness of the BCW 2x2, especially on 2x2s with larger window sizes. Totally satisfied with the BCW pages. I won't be buying Lead Dog pages from my local dealer (or my local coin shows since that's the brand that's sold there).
Hope this helps someone.