What is my XYZ worth? How much is THIS worth? Value my...

I have this. Bought for a friend about five years ago. Friend never paid, so I got lumbered. I'd like to see the back of it this year. Not really sure what to sell it for?

I would keep it, but any of you that have met me will know it's a teensy bit small.

Cannondale R800 CAAD8

Frame size – 54cm

Frame colour – Matte Black

Fork – Cannondale Premium full carbon ( 1 1/8” carbon steerer tube )

Wheels – Mavic Aksium ( Silver )

Chainset – Shimano Hollowtech II 105 Compact double ( 50/34 172.5mm )

Bottom bracket – Shimano 105 External

Cassette – Shimano 105 12 – 25 10 speed

Shifters – Shimano 105 STI 10 speed

Front mech – Shimano 105 Double

Rear mech – Shimano Ultegra ( short reach )

Brakes – Shimano 105 Dual pivot ( 49mm standard drop )

Brake levers – Shimano 105 STI

Chain – Shimano 105 10 speed HG 5600

Seatpost – Cannondale carbon fibre ( 27.2mm )

Saddle – Planet X superlight team with Titanium rails

Handlebar – Cannondale Fire Aluminium ( 31.8 clamp, 42cm wide, 140mm drop )

Stem – Cannondale Fire Aluminium ( 31.8 clamp, 120mm length )

**Headset **– FSA intergrated ( 1 1/8” )

Tyres – Hutchinson Top speed ( 23mm )

Pedals – Shimano PD M540 SPD