Critque my build list/cost?

[shiftpdn]

I'm looking to do a donkey kong cabient scratch build and I've plotted out the total cost in excel. 
Graphics   
Marquee   $39.95
Control Panel   $32.99
Bezel   $39.95
Side Art   $62.99
   
   
   
Electronics   
Coin Door   $50
I-Pac   $35
Joystick   $9.9
Pushbuttons (3)   $7.35
Monitor(used)   $30
PC (used)   $50
Speakers   $10
   
   
   
Construction   
MDF 3 sheets   $60
Casters   $6
2x4 interior   $20
Paint   $30
T-molding   $15
Marquee Light   $35
   
   
   
   
Grand Total:   $534.13

I'd like to have the functionality of MAME so I'll be using a computer instead of a DK board.  Any comments, advice, etc?

[milkit]

dont forget to factor in a tmolding slot cutting bit if you dont have one.

$35 for marquee light? jesus! haha. 18" under counter fixture + bulb is $7 at walmart. However, get the $17 led marquee light from groovygamegear.com IMO. Its awesome and wont burn out 10x a year

[BobA]

If you have a well stocked shop you do not have to worry about odds and ends such as screws, nails, glue, sandpaper, wood filler, tack rags etc etc.   If you do not you can easily spend another $100.

[syph007]

I had a build/price list at the start, but ended spending double.  There are always msc things along the way, so Just expect more hidden costs.