you may send more baggage by courier. for the first time, extra baggage coming by courier will be exempted of customs duties. from second time onward will have to pay custom duty......
If you declare goods with receipt during your landing , you wont need to pay duty even you bring those goods after 5th time .
All you need 2 sets of receipt and photo of all goods which you think you will bring them at later stage to Ca .
Baggage policy is diffrent from carrer to carrer and even diffeent in same flight .
Check with booking agent , also dont book flight online without cheacking and confirming bagage allowance with airlines/agent.
Also if you are frequent flyer then you can get 10-15 kg extra luggage depending upon your airmiles prog . As i always use Qmiles or miles n more card. No matter whichever airline i fly . So i get 10 kg extra allowance on most of partner airlines (from Qmiles. Or Miles'n'More )
One of my friend bought 23kg extra bagage for £40 from UK on top of there 23+23+7+ Lp top bag allowance .
So always check at few places and ask travel agent to call airlines in front of you to enquire about extra bagage etc .