:imo: I probably want a little more information. Especially on how much it will take to break your wallet. ::
There are basically two kinds of "kits" available.
The easy ones are made by places like Lyman with their Great Planes Rifle, or Thompson Center with their Hawkin or Dixie Gun Works with their Pennsylvania Rifle and Super Cub Rifle.
These gun kits are pretty much finished by the factory. The main things which are required are trimming a little wood to finish inleting the lock, barrel and trigger guard, draw filing the barrel, sanding the stock and applying a finish to the wood.
I would guess it would take a beginner from 1 to 3 weeks to finish them. That's working 1 to 3 hours a day.
Dixie has a few "kits" like the Tennessee Mountain Rifle and the 1861 or 1863 Springfield Rifle which they list as a Skill Level 2 which requires some stock shaping, hole drilling plus the things I listed above.
I haven't worked on one of these but I suspect you might add a week's work to cover it making it a 2 to 4 week task.
The easy kits vary in price but you can expect to pay somewhere around $250-$350.
The more difficult factory kits are in the $425-$650 range.
You might notice that the prices of these kits is almost as much as the finished gun. I think the reason for this is that the big companys know this is a fun hobby so they are taking advantage of that fact and charging accordingly.
The other kind of kits make a big jump in difficulty and an increase in price. The quality of the barrel/lock/trigger etc are the best in the world.
These are sold by places like Chambers, Track of the Wolf, Pecatonica River and a number of other places.
These kits are little more than the Lock, Stock, Barrel and Furniture (butt plate, trigger guard, sights etc).
The stock is rough machined leaving anywhere from 1/16 to 1/2 inch of wood on it.
The inlets for the lock, trigger etc is usually very rough so these parts require quite a bit of work to fit.
The furnature is made of rough castings that require filing/sanding/polishing. None of the screw holes or mounting pin holes are drilled...
I could go on, but suffice it to say these kits take a lot of work.
I am slow and careful but I figure it takes from 250-400 hours to complete one of these kits.
The prices of these is largly dependent on the type and quality of the stock wood.
For a full stocked Kentucky style rifle the wood can cost as little as $110 or as much as $250 or more.
The basic parts without wood will cost from $250 on up.
I don't want to scare you off, but you need an idea of what will be envolved before you put your money down.
If your interested in this level of a kit, read as many posts on Builders bench as you can. Find out what problems others ran into so you can get a feel for what you will have to do.
Take a look at their finished work to see how the kits at this level can turn out.
No matter which type of kit you choose, I know, in the end you will be pleased with your work.