I want to get into shooting flintlock rifles, my question is; Do I need to spend big money to get started ?
It depends on what you call,
"big money".
You're looking at about from $975.00 to $1050.00 to start. For what you can buy in stock today, I'd say you want either the less expensive Pedersoli
Traditional Hawken in .50, or the .54 caliber Pedersoli
Frontier rifle..., the more expensive of the two. I have owned a
Frontier, and they have nice, robust locks, and shoot well. ALL flintlocks have their quirks, and you need to learn these when you get your rifle.
The advantages of either are, you can order it today and have it soon, which gives you all summer to work on learning to shoot it. They are not custom rifles, and will take some banging around in the woods, and you won't feel bad when doing so. Either one should shoot well, and will take large game. IF you'd prefer a .45 or a .36 the Frontier is available in those calibers too.
Used... if you can find a used Thompson Center Hawken or Renegade in flintlock, with a good bore, those will also do well. They may run between $450-$600.
Other than those options, yes you can get a more expensive rifle. Will it shoot better than any of the above..., it might, but it might not. Will it make deer any more dead than the factory rifle, NOPE. Will it be more historically "correct", oh without a doubt.
Only YOU can determine what you need in a rifle.
The more expensive semi-custom rifles, will have more attention to detail, so better wood to metal fit, usually, and probably a higher quality of "figure" in the woodgrain of the stock. Will the barrel be better? On paper, but will you be needing to take advantage of that? The Lock will be better but whether you notice that will be subjective. Which means if your factory rifle shoots inside a 6" circle at 100 yards, and my semi-custom Cabin Creek rifle shoots just about a 4" group at the same distance..., will the deer know the difference? It will make a difference at a shooting competition, but not in actual application (imho)
LD