Pro perks would be too OP if they were bought. You should earn them through a challenge or two, because if you really want it, you would try for it. Here is a list of the perk, its challenge(s) and pro functions:
Quick Revive:
Regular: revive team mates faster (solo revive self, 3 uses)
Challenge: revive 5 team mates (don't go down for 3 rounds)
Pro: revive team mates in one tap of action button, they get their perks back (solo: keep perks when downed, pro perks downgrade)
Juggernog
Regular: 5 hits to down
Challenge: take up to 3 hits at once 2 times
No hits for 1 full round
Pro: health regenerates faster, 2 meter motion sensor with mini-map (to see around corners)
Speed Cola
Regular: reload faster
Challenge: kill 10 zombies, reloading between each kill
Go 1 consecutive round without buying or using grenades or equipment
Pro: switch weapons, prep grenades, and prep equipment faster
Double Tap Root Beer
Regular: bullets shoot 2x faster
Challenge: avoid having less than 1 full mag left in your gun for one round
Do not use grenades (lethal&tactical) for two consec rounds
Pro: + 4 lethal + 1 tactical grenade, 2x reserved ammo (when pro is unlocked, it acts as a max ammo)
Phd Flopper
Regular: no fall, explosive, or splash damage, explosion upon dolphin dive impact
Challenge: flop 50 zombies
Hold a grenade and kill at least 1 zombie 5 times
Run through one trap
Pro: flop on flat surface, jump higher, immune to traps, danger close pro (MW2-explosives carry more damage)
Stamin-Up
Regular: Move faster, sprint longer
Challenge: survive one round without sprinting
kill 50 zombies crouched/proned
sprint 1 mile
Pro: become very thin ( to squeeze through tight spaces), eternal sprint, stand/crouch/prone faster
Deadshot Daiquiri
Regular: increased headshot accuracy while ADS, smaller crosshairs
Challenge: headshot 50 zombies
Hipfire kill 50 zombies
kill 50 zombies while moving
Pro: steady aim pro (BO)(recover from knife lunge quicker, bring weapon up faster after sprinting), hardened pro (BO)(bullets penetrate surfaces, no flinch when hit, reduced recoil), stalker (MW3)(move faster while ADS)
Mule Kick
Regular: wield three weapons
Challenge: get 1 pro perk
Pack-a-punch 3rd tier weapon
Survive 1 round
Pro: perk cap + 1, perks downgrade after downage (ex: flopper pro to flopper, juggernog to none)
When Mule Kick is bought after respawn/revive, third gun is retrieved, upgraded, get back 5th perk (not pro)
Pro names (in above order):
Perk-o-later
Circle Linebacker
Sleight of Man
Ammo Magazine Subscription
Dr. Phlopper, MD
Wait Watchers
Steady shot stackery
Back-a-Bunch
Rhyming names (for fun):
Richt's alive!
Hug her frog
Weed stola
Bubble Snap Boot Rear
She hates me, Cropper
Flamin cup
Head shot smackerie
Stool Trick