Where to find non-painted, affordable wooden building blocks?

we have some from ikea. they came in a fabric bag with webbing for handles and a nice little tie-closure. i am not sure if they still carry it though....

Try Etsy. There are lots of great blocks on there.

http://www.etsy.com/view_listing.php...n=&max=&order=

http://www.etsy.com/view_listing.php...n=&max=&order=

The above are great ideas, but I also wanted to point out that I often see ads on Craiglist for wooden toys that someone makes as a hobby.

I'd look for a local woodworker-even a newbie woodworker can make some great wooden blocks. My Dad makes DS's blocks and other wooden toys and they're indestructible. Plus, if you find a local craftsperson they may be willing to use recycled lumber from a Habitat Re-Store (which is what my Dad does most of the time).

We have Brio brand blocks. Very nice smooth finish (unpainted) and a nice heft to them. Lots of different sets to choose from with many different shapes.
We have the 50 piece set for about $15.

Try your local consignment shop or put an add on freecycle. I got a whole tub of wooden Brio blocks in various sizes from an add on freecycle (along with a classic sit & spin!). Our Kid 2 Kid always has the plain & colored ones...it's a little pricier than regular consignment shops, but they only take the best stuff.

I really don't like painted Melissa and Doug stuff, but they have a nice unpainted block set that comes in a sturdy wooden box with handles that Amazon has for around 30ish dollars (I think?). DD loves them, and my inner math geek enjoys how they fit so nicely back into the box like a puzzle.

Try Discount School Supplies-- website and catalogue. My mom found some for DD there for a not crazy expensive price, but they are maple and will stay nice forever.

Our wood blocks are comprised of three different finds.

One at a yard sale for a bunch of larger natural wood blocks.

Another good size set of smaller blocks set at a yard sale.

And then another find at a thrift store...these looked the same as the first ones we found at a yard sale.

So we have enough to fill a short rubbermaid bin and we probably spent $10-$15

We too have the Melissa & Doug unpainted blocks and so far, so good. I think their price is very reasonable for what you get, and I agree that M&D quality tends to be a bit wonky which is why I typically avoid their toys. I felt okay about the blocks because of them being unpainted.