Hi!
What I am not familiar with:
a) hledger. I have always used GnuCash for my accounting needs.
b) The ports system. I am mostly a Debian guy, so I am very familiar with the Debian build system instead.
What I'd dare say I am quite experienced with:
c) Haskell. It's been my favorite language for the past two years, and I use it almost exclusively for my personal projects.
d) The *nix/free software ecosystem/community/way of doing things.
So, if you don't get any better offers, I am confident I can have a package ready within 7-10 days. I can't promise it will be included in the ports tree, but I can promise to submit it and work through the issues that arise.
Other than that, I'd love to work on this project, I am usually doing this kind of thing as a pastime.
Thank you, best regards, Panos