I ship from France where the overseas postal rates are quite expensive (similar to yours) especially for parcels. In France if the thickness of your parcel is less then 3 cm it is considered as letter and the rates are much more interesting even with tracking. So, the solution for me is to paint on thinner panel or paper, or on canvas and not to frame it. I send by international letter with tracking delivered against the signature. I have also to choose between 2 insurances depending on value in case of lost. French Poste has information from USPS untill the letter is delivered. Probably it will work the same way in Finland? As for framed works I indicate the real cost or put a little bit less in shipment but arise the price, all the same, you have to fixe for how much at the end you are ready to sell your artwork. In all cases, I prefer to send with tracking + signature. I think it is more reassuring for buyer and for me and I guess it is mandatory for PayPal in case of dispute (hope never to have one!). Hope this helps…