On a serious note..........
It's worth what you'll pay for it. I mean, if it's in a really clean cab, with good art, plays great, and everything works... it's worth could be $100 - $750.
If the cabinet is in bad shape, but the games in good shape it could be worth $0 - $200.
Factor in all the variables:
Availability of arcade cabinets where you live
Desirability of the cabinet where you live
Condition of the cabinet
Condition of the artwork
conversion vs. dedicated
Bag of parts - what would it cost for you to build something identical?
I guess what I'm saying is... I don't know. You don't give enough details, and since you didn't I'm going to make some assumptions:
You live in Alaska with a small population
90% of the people who live within 300 miles of you are avid Street Fighter collectors
This is the only Street Fighter cabinet in the state
The cabinet is excellent condition
The artwork is perfect
It's a rare dedicated cabinet signed by the developers at Capcom
My original estimate stands: $1,203,468.82