My friend, you have a long way to go, with plenty of options
Here is my mod list...
Window Tint (previous owner put it on) - $0
Interior LEDs (previous owner put them in) - $0
DiodeDynamics Always-On Module - 59
Black Steering Wheel Trim Piece - 27.40
OEM Armrest - 200
OEM Audio + - 1499
D4S touch-up paint - 14
Fatmat Sound Deadener - 55
Luxury Liner Pro Sound Deadener - 70
25mm/30mm Spacers - 267.70
Side markers - 50
Camber bolts - 24.24
Lowering Springs - 180.97
Exhaust Tips (for OEM exhaust) - 80
Tein Flex Z Coilovers - 795
Ambit RE02 Wheels - 500
Hankook Ventus V12 tires - 615.15
Mount tires on new Wheels - 150
Rear CARSMO Spoiler (already painted D4S) - 300
Vibrant Exhaust Resonator - 50.59
Muffler shop work (to get resonator placement right and some other stuff) - $100
Resonator install (second round of placement) - 60
Upgraded Trans fluid - 66.72
BasonR Front lip - 65
Crystal Eye Tail lights - 250
Sprintex 210 Supercharger - 2050 (included shipping and extra pulley)
TopSpeed Axleback Exhaust - 400
Extra midpipe (since I want to retain all my factory OEM parts and I already had the resonator welded into my stock midpipe) - 50
Anarchy Motive Shift Knob - 85
Bendy-Arm Phone Mount - 20
Shitty Lug Nuts - 25 (regret... but... not willing to pay 150 for lug nuts)
Window Visors - 50
EcuTek license - 350
MotoEast Tune - 200
OFT Tuner - 425
Gruppe-S UEL header - 515
MTEC shift springs - 38.09
Raceseng Sprintex 72mm Pulley - 100
Redline SC oil - 19.40
Motor Oil - 170.11
Local Performance-Shop Alignment - 185
Stock Tail Lights (to be painted -- broken by accident) - 100
Front bumper (replacement with paint) - 550
Front bumper repair (my DIY attempt before I caved and bought new bumper above) - 75
Shorty Antenna - 20
'Supercharged' Badge - 11
Moto East Flex Fuel kit - 550
Android HeadUnit Stereo - 305
Subaru Blue Coolant - 30
Sold: OFT (-400), Spacers (-100), Lowering Springs (-75)
Total: 11228.37
+ 2013 Car (22,000) + Taxes (1700)
Grand Total: 34362.37
EDIT: Planned mods: Hmm... maybe some catch cans. Maybe an oil cooler at some point (oil to water), but no real need while running E85 so far on street.