I'm having the same problem here... with a 2007 model...
I've read all of
@Martin-Brighton-uk's issues and it looks like the same issue but worse
Look this
All parts £1694.68
Mechanic: £780.00
(The prices below are in Brazilian currency)
T1180238 Gear input 5A 1 R$ 632,00
T1180235 Gear 3RD/4TH 1 R$ 787,00
T1180236 Gear output 3 MB 1 R$ 778,00
T1180061 Gear 4TH output 1 R$ 960,00
T1180059 Gear 5TH output 1 R$ 804,00
T1180058 Gear 1A output 1 R$ 898,00
T1190650 Selector Fork 1A/4A 1 R$ 569,00
T1190655 Selector Fork 5A 1 R$ 569,00
T1190660 Selector Fork 2/3 1 R$ 799,00
T3990089 Gasket kit full 1 R$ 3.590,00
Oil Filter – 1 R$ 453,00