I'm going to go on record and say that crafting the holiday badge, especially to some of the ridiculous levels I've seen, is a waste of money.
The average price to complete the badge right now is about $5. Even if you get all of your cards from buying games and crafting other badges, your trade off is still $5 you could have in your Steam wallet to buy more games.
I guess there is an off chance that you'll craft the badge and win an item that's worth more than $5. But still, I don't think I'm going to craft even a level 1 badge this sale.
If the last sale with cards is any indication, they will be super cheap after the sale and you can buy them for pennies and craft badges then.