Modern bike has some options that are pretty close.

https://www.modernbike.com/sugino-xd600-cranksets

https://www.modernbike.com/origin8-t...48-38-28-black

https://www.modernbike.com/sr-suntou...8-38-28-silver

https://www.modernbike.com/sunlite-a...2-42-30--black


Unrelated, but this is a fantastic deal.
https://www.modernbike.com/sugino-xd...110-175-silver

Hmm, and here's some bare cranks that would work for you, if utilizing your already existing 50/34 rings.
https://www.modernbike.com/sugino-xd...110-170-silver

And the cheapest chainring I coudl find on ebay: https://www.ebay.com/itm/QBP-Chainri...gAAOSwr8he3lQw

edit: Forgot you want an inner 28t/30t ring. Here's a 30t campy ring for $20.
https://www.ebay.com/itm/Campagnolo-...4AAOSwBY5d03DH