just Fast Q i need help

That depends on you. I'd sell them, wait for a sale and buy new games! :D

the real question is...
do you want to level up your steam account, or fill your steam wallet?

I personnally sell the cards more expensive than 0.05$ and craft with the cheap ones (higher level = higher chances of getting card boosters)

1000 Steam cards, that's around 40-60$. I'd sell them. Be warned, there is a limit of 200 transactions per year. If you want to sell all your cards, you'll have to fill a questionnaire (name, address, etc).
You also can trade them on Steamtrades for bundled games.

I would sell them