General

Interior and exterior panels are $1/sf. Are there any other options?

Indoor

Beadboard - 3/8" interior, $22. [1]
Prepainted, but 1/6" - $20 - [2]
Prepainted beadboard - 3/16" - $11, but 3'x8' in size [3]. And needs nail/adhesive installation.
Prefinished 1/8" - 4'x8' - $15 - [4]
MDF finish panels - $11 - [5]

lathing strips - $33/50 of 4' long [6]
$18 for 50 - 36 cents each - [7]
Cost per panel - uses 9 strips - $3.24 per panel.
You can rip your own lath from 2x4s with 0.1 kerf blade [8] to get 10 lath of 8', 20 lath of 4'. 20 lath for $6 2x4 prices of 2020. Or $15 per bundle of 50. Reduces lath cost to 9/50*15=$2.7 per panel.
But, install requires panel glue, not nails. [9]

Cost is $1/2 per sf for materials, and $1/sf for labor. [10]. But that's just to hang. For finishing up to painting - it is $2-3/sf. Compare to beadboard industry standard of the Seed Eco-Home, at 75 cents/sf materials and DIY technique - and it's 3-4 times less costly.
Compare to costs for an entire house - [11] - and note that drywall at $5-19k for a whole house - compared to $1.5k in beadboard for all the walls and ceilings. Drywall appears to be 3-12 times more expensive if you hire out, than if you do beadboard DIY.