Good idea fer startin out with flints on squirrels. That's what got me hooked. The opportunities to shoot a deer can be few and far between. If you didn't do your part in making it work - you can get frustrated by having to wait until next year for the next opportunity.
However, with squirrels if you make a mistake and your pan goes poof but the gun doesn't go boom, you just correct your mistake and wait another 10 minutes. Eventually you feel comfortable enough to try it out on deer. In the mean time, you'll find that a .36 flintlock will make squirrel hunting extremely enjoyable. To the point where you look forward to the squirrel opener as anxiously as you do the deer opener.
$2000 will get you 2 semi-custom flintlocks of excellent quality. You may not get much fo-forah with them, like carving, inlays, and tiger maple.
I've got a semi-custom Early Virginia with swamped barrel and Jim Chamber's Colonial Virginia lock. I was a couple hundred short of the $1,000 mark. So the components are what you would find on a $3,000 gun, but mine just lacks the fancy carving. I'm working on my own type of carving and inlay. "That clover-leaf there just behind the entry thimble, that's from hunting Wildcat Mountain in 2004, I got 2 does that trip. And the little crystal embedded on the cheek, that's sand from when I was. . ."