Hey there,
I recently emigrated from Ireland to Nz and brought a bike with me Gl1800 Goldwing.
Costs were:
Cost of buying bike(varies

)
Crating. Box needs to be fully enclosed. Must be Mdf/plywood/hardboard or metal. (no natural woods or you run into legislation (ISPM 15) that requires a heat-treated stamp). iirc a plywood box for the tenere in 2010 cost me 4 sheets of 24mm plywood,nuts and bolts, and a metal shipping crate i got for a small fee from Yamaha in Dublin. @€200
Sea shipping @€150 per m3 plus port fees in Nz (about the same again-little less)
Shipping agent fees NZ: Tried to avoid these but failed. $200nzd iirc
Gl1800 took up 4m3, but was also packed to bursting with personal goods.
A 750 Super Tenere I sent to Usa in 2010 took up just under 3m3 iirc. (front wheel/screen removed etc)
Dr650 etc is similar. You will save about another m3 if you also drop the back wheel, but you have to build a frame/clamp the axles(replace with waterpipe-dont use the axles as a mount point) to hold the bike.
Customs/biosecurity fees: $40nzd for customs, $130 for biosecurity iirc(without extra fumigation etc-bike must be clean).
Both agencies were efficient and lovely to deal with in Christchurch. Took @3 days to get the bike after arrival.
I then had to Register the bike and get a Warrant of Fitness as I was staying. A temporary import doesn't need this. Also, you cannot sell a vehicle here within two years of import or you have to pay Gst(tax) at 10% on the imported value.
Were you to permanently import a bike and then sell it, it would cost circa $400 for the initial WoF and Registration.
Going by those costs, sending a bike over and back may also be an option if you already have one in Ireland depending on your overall plans.
I sent the bike with Brendan Daly in Dublin, on 01 2836077.
Additionally, Brendan moves a lot of Irish people to Aus/Nz. Most go with full/half full containers. It might be an option for you to piggy-back at much reduced shipping rates if those people agree to it. Up to you to look into. Brendan is very good to deal with.
Hope that's of some help.
Cheers,
James