There are a few great surgeons for overall hair loss but if you want hairline specialists, I would focus on these guys in the US personally.
Diep, 7 us per graft so at 2000 = 14k
Wesley, I can't remember his prices off hand but I'd guess in the 7-10 range per graft. NY based it's always going to be a little more.
Diep is the probably the most aggressive hairline doc in the us, really works well with younger guys but if you want a more natural look that still brings out your best Wesley is awesome too. Dr Shapiro and Dr Konior also both do outstanding work in every aspect so you never lose going to either of those guys but for hairline specifically I would personally go with the 2 I said.
In Canada
Dr Rahal is I believe 8 per graft for the first 2k then 6 per graft after + tax. Canadian dollars tho so there is a discount for the American using canadian currency and he does have a 1k travel allowance.
Rahal is like Diep, both are hairline gods and agressive. Rahals team is proficient in fue but their expertise is in fut. If I had to stay North America I would lean Diep just as hes more fue oriented.
In Europe
the upside to Europe is the sheer number of fue surgeries they do, in the us it's more like 75 percent fut and 25 % fue for docs who do both and very few do both well. In Europe it's more like 85% fue 15% fut. They are the leaders in fue and they teach the americans how to do it, literally the conferences are run by these guys. And it's usually a bit cheaper even after factoring in travel.
Dr Feriduni - 5 euro per the 1st k then 4 euro after I believe so 9k euro for 2k
Based in Brussels, also charges VAT @21%
Dr Bisanga - 5 euro per the 1st k, then 3 euro after. so 8 k euro for 2k and if you get a drs note he'll waive the vat. This was my doctor, also in Brussels
Dr Erdogan - 2,5 euro I believe across the board. Based in Turkey
Dr F and Dr B, if you ask other doctors who they would want to design their hairline and do their hair surgeries these are the names that get brought up. I asked every doc I consulted with and they are brought up 80% of the time. I would ask a doc in the us and he'd tell me go he'd go to Dr B lol They are the best of the best in fue circles period. Dr Erdogan right up there with any of the hairline guys, very talented doc and gets some of the craziest densities around but he does it by using more grafts than anybody else. If you're 2k with every other doc, you'll be min 2500 with Erdogan and likely closer to 3k. So if you don't have a lot of loss and don't see your hair loss progressing and can afford the grafts then Dr E is a great way to get as close to your normal hair as possible but if you see progression coming down the line, he can lead to some graft wastage and you need to preserve grafts. He makes all the other agressive docs look timid lol
Those would be my recommendations