For some reason when I try to buy the Frostpunk+gift bundle, it says I can't because I need to have Frostpunk to buy the dlc. Anybody else have this?

Yes .

Sounds like they did a bit too good a job of prohibiting people from buying it

Open a support ticket.

This offer expires June 23rd and support aren't typically speedy. What you could do is check "Gift this order" on the checkout page. Then send the code to your own e-mail address. Redeem the code afterwards.

The gift method doesn't work. You still cannot redeem it, so do not try it guys!

I sent a screenshot of the hilarious page you get at the checkout screen. Highly doubt I'll have any chance at getting a response in time knowing my luck though. Somebody really messed up by flagging it as if it's DLC that requires both Frostpunk AND the Last Autumn DLC when the requirements to buy the package sale are the literal package contents already.

SMH

Then either way you need to open a support ticket, but if you buy it as a gift, you do so at the currently discounted price.

Frostpunk + GIFT DLC is

"This pack contains Frostpunk with Frostpunk: The Last Autumn as a GIFT. "

but to buy it you:
"Please note that you are required to own Frostpunk AND Frostpunk: The Last Autumn "

so what is the point of this?

Basically sounds like, "Screw you, no gifts".