I share your frustration. The heart of the problem is that a well made bike in 20" kids size can't rationally be expected to cost much less to make than the same specs on an adult bike, and the fact that most parents don't care about quality means that there isnt much of a market for good bikes, and resulting competition, and therefore much new price cutting or presence on craigs list of decent bikes. When you combine that with the fact that is likly the bike you kid will be exposed to the most learning, falls etc on and you have a no win frustration, unless you are rich.

Do take heart though, kids are resilient. You are just not going to get something they can bang around that also has efficiency that allows them to go on 40 mile rides with you.

And look for the sales: performance went down by 40% on it summer sale and REI goes down 20% in spring and 15% in fall

By the way, get the assembler to throw on a bash guard over the derailleur. kids are totally random as to which side they lay the bike down.

Also when think about how much money, consider bike theft in your area. I live in a high theft area, meaning I have to have two locks for my kid, a light one for her to carry and a heavy one for her to leave at school. Still even the most careful kid is sometimes careless, and you have to consider that before dropping the maximum you can spend. (for my part I am happy the scamp has no quick release seat, and I intend to reemove the quick release on the front wheel)

the only other advice I can give is that if money is an obejct, and you don't have follow on kids, others should do what you and I didn't -- start to look on craigs one year ahead!