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https://en.wikipedia.org/wiki/List_of_Humble_Bundles
A quick google would have got answer for you
I used the add on to check but didn't see anything.
edit: I still don't think anyone would have a spare Starbound key to trade that bundle, though. 2014 is quite some time.
I never had the game to trade, but since Starbound has been long gone from its bundle days I don't think anyone will do this trade unless Starbound gets bundled again. For now, I'd say Starbound is worth more money than Stardew is because they both go on sale for the same price, but Stardew is getting bundled a lot while Starbound is not.
Maybe you can find someone who wants to do a 4-pack when it goes on sale and trade a copy instead. Good luck.
Stardew valley
Other games from Humble Freedom bundle
Starbound
Or have anything else from Humble freedom bundle
1:1 trade only - they are same price and Starbound was in a Humble Bundle before too.