I'd agree these aren't the best deals, but if you've already bought something, they aren't horrible to add on for free shipping. I've seen them cheaper on other deal sites, but shipping can be close to $7.95 on some.
Now for product reviews based on my three year old son's experience/my observations. We have the clock, the farm animal cube puzzle, the stackable nesting boxes, and the geometric shape sorter.
The clock: my rec. age 3 up. Probably my fave on here. My son adores numbers and clocks, this incorporates shapes, which helps with number sequencing, as the shapes fit in only one spot. Solid piece. I bought used for $5 and still looks brand new.
Farm animal cube puzzle: my rec age for general play: 1+ (block stacking), for actual puzzle use, I'd say almost 4&up due to difficulty/attention span of avg child. Durable puzzle, wooden box that holds is pressboard/wood combo, and is less durable. We've had to wash some pieces, and the images stayed on, but scrubbing not recommended.
Stackable nesting boxes: made out of cardboard, so durability is iffy. Not very washable, but wiping off has mostly kept in good condition. My son adores the stacking and the nesting ability, but mostly beginning at age one, loved for us to build it so that he could see the whole tower come crashing down. There are all the letters of the alphabet on the boxes with animals to match.
Geometric shape sorter: My son loves stacking the different shapes, and has since he was two. The only issue I have if you could call it that, is that there are so many similar looking shapes, that he sometimes just slides the box open and drops the block in (as if he has somehow outsmarted the system).
Update: We also have the geometric stacker. That is my son's other favorite. I love these, though they seem to end up under my feet the most in the dark... And yes, it hurts. I highly recommend hiding that little red wooden ball block on top... Kids will try to throw balls in the house, and again... It hurts. Trust me on this one. ;O
I have found Melissa and Doug toys to be mostly well made, with the exception of their durability under water. Even products that seem they should be able to be washed easily warp if dried incorrectly. I recommend their products, but also a smidgin of common sense to go with it.