I’ve been to Kona several times and I don’t recall ever seeing an official Ironman merch shop.
Beyond a couple little things here and there, the sign on Ali’i Drive that denotes the start/finish and the murals in the Marriott, you wouldn’t even know it was there. Some shops might have an Ironman sticker in a window or door but for the most part it’s only Ironman nuts around the race date.
Quite a few of the retailers/t-shirt shops on Ali’i within a half mile of the pier sell Ironman branded swag. The selection is mostly t-shirts, hats and few other things but it’s not an impressive line up. Nothing like what’s available at the race-week retail shop.
last few times i was there there was ‘a’ shop - not sure if it was official or not - selling a fair bit of Ironman gear. It’s on Ali’i, maybe 300 yards from the Courtyard Marriott, on the inland side. I seem to remember some sort of Mdot sign on the outside FWIW…
I was in Kona last March and found a shop that had tons of IRONMAN merchandise. I was able to pick up a T-Shirt, water bottle and had a great conversations with the owner who have raced several years. He even gave me the pervious years poster and program. He carried several other IRONMAN items in the shop as well. It was slightly limited, but more than I expected. Unfortunately I don’t remember the name of the shop but it was off of Ali’i somewhere near the Fish Hopper. There were 3 or 4 steps to get up to the entrance. I also noticed items in other shops in Kona. While there was nothing official, if they look for stuff I’m sure they can find some.
MattyBoy and jpicune are describing the same place, and it’s the one I thought of when I read your question. There’s a shop on Ali’i drive, mauka side, that’s one of a small cluster of souvenier-type shops very close to the pier. It’s no more than 1/4 mile from the King Kam. I have no idea what its name is, but it advertises “Official IM Merchandise.” They’ve got a lot of different gear. It fronts Ali’i (i.e., it’s not tucked away behind another shop), but you’ve got to walk up three or four steps to get to it.
You want to check out Unison Hawaii. They have a great selection of ironman product the week of the race. Good chance they will have leftover product still.