Onan Cummings 11kW generator part alternatives

As the Onan mdkbm 11kw has a Kubota engine (4cyl 1498cc ) I assume that the Kubota and generic aftermarket parts are a lot cheaper than the Onan Parts ?

Kubota D1105 is the base engine

But here are the/some partnumbers
starter motor :
Denso 228000-5911
Kubota 67980-31152

Oil filter
Onan Cummins 185-5835 (35 euro ex vat)
Kubota HH160-32093
Bosch P3372
replacement (3 euro incl VAT)
Fram PH5317 (10 euro incl VAT)

Fuel Filter
Onan Cummins A026K278 (62 euro ex VAT)
Kubota 15221-43170
Beta Marine 211-60210 (20 euro incl vat)
BOSCH 1-457-434-069
Fram P6503 10 euro incl vat

Impeller  JMP 7110-01
Onan Cummins 132-0498 (65 euro ex vat)
generic replacement 29 euro incl VAT
http://www.dintra.nl/ 18 euro incl vat

Zinc pencil
Onan Cummins 130-4434 (18 euro ex vat)
Beta 209-61840 (20 euro incl VAT)

V belt
Bando 2375 95x950La
Onan Cummins 185-6934 (48 euro ex vat)

Stop solenoid
Beta Marine 600-79660 around 150 euro
Kubota 17208-60015 & 17208-60016 around 75 euro

Illustrated parts list

Kubota D1105 parts manual

BV1305 Manual and partslist

Onan manual