OK the price difference is $3200 which you can drive a used Stern pin thru.
However I have heard of people already adding $1300 to the pro from Refinery for extra Bling so there is a definite amount of people that would bling a pro without changing the actual playfield like the premium and LE do.
I agree the differences are mainly cosmetic such as colored legs or wider side rails and head emblems and etched side rails, but there are some functional differences such as kick back, VUK, metal ramps (just a few that I can think of).
Lets just say you buy both and want to sell both later on, assuming the pro does not play better than the LE (which I don't see anyone saying) resale your LE is going to be worth ~$1200. (I don't doubt that) suppose in the future you want to sell ST pro for $3300 you could sell a LE for $4500 (I don't doubt this) Let's just subtract $1200 off the top. - This includes the signature and rarity factors.
So down to $2000 difference.
I am going to round to nearest $100 just to make it easy.
-Shaker I would put this value at $200
-60 RGB inserts, I am not talking the price of the bulbs, I am talking if someone wanted to make a mod for the pro along the line of Eli ramp for Tron. $300
-Side cabinet emblems, mirrored back glass, and speaker trim $300
-Etched and lighted side rails (Bling Bling) this is a better looking exterior trim package than I have seen it looks pretty f-en cool. $300
-Extra movement on spaceship, Enterprise toy, kickback, up kicker, metal ramps, warp chase lights, disco laser and asteroid flashers (meh) but I'll say $400.
-PF support rail and lockdown bar, color legs and side rails $200.
$1700 for 'added features', was looking for $2000 so it's a net $300 more than the 'book value' I have priced the extras at but other than the shaker and the Enterprise toy, asteroids, most of these features would be hard to add for instance kickback would be no code etc...
So, if you would want most of those bling things such as 60 RGB led's, etched siderails, color trim, metal speaker trim etc.. and then you prefer the art some amount to make up the extra $300.