I just got my T5 gearbox rebuilt for $935.
The Daily VN T5V6
LSD : SS Kit : Calais Rear : Calais Dash : Climate Control : Power Windows : More...
355 VN GRP A REP
All New Suspension : 322mm Brakes : 3.45 LSD : T56 Gearbox : Group A Kit : More...
I dont think you would need to rebuild it, just replace that one synchro.
What i got done was basicaly replacing everything except the actural gears themself.
The Daily VN T5V6
LSD : SS Kit : Calais Rear : Calais Dash : Climate Control : Power Windows : More...
355 VN GRP A REP
All New Suspension : 322mm Brakes : 3.45 LSD : T56 Gearbox : Group A Kit : More...