I've been using
www.findchips.com.
On another note, I use a LOT of CR2032 and LR44 batteries and I use these
**broken link removed** guys in the US. The substitutes don't work well.
The retail price when Radio Shack was around was like $5.00 each. I just checked another option $2.59 USD, but I have to order and pick up. The company offers free shipping when you pick up an order to a local location. It may take a week. If I order direct, it would be here the next day for about $10.00 postage.
So, as alec said a lot goes into trying to find the best "overall cost". Let's not use price here. Infinatelights offers free postage for orders over $15.00 and 10+ CR2032 batteries are $0.89. Digikey, I believe has them cheaper, but not necessarily with postage. My order is usually about 20 Cr2032 and 10 LR44's.
I made a very effective and easy to use laundry lint filter, basically using modified commercial parts:
Filter Holder and some fittings - aquarium supply store
Clamp and washer - Vendor #2
New Hose - ebay - Vendor #3
Filter - Vendor #3.
Hardware store
Each one, except ebay can add ~$10.00 USD for postage, but I did not have much of a choice. The filter went through three iterations over time. Bag selection mesh size and material for cleanability. Before the special clamp, I used a hose clamp, nutdriver and thick washer (plumbing part), but it was a bit inconvenient. For th final design, I used a friend's lathe and drill press which he doesn't have anymore. It's simple and maybe > $100 USD. It's still cost-effective because renting a auger and the the inconvenience, The clog happened to be about 25 feet in in a galvanized pipe in/under the basement floor.