Sometimes the volumetric weight of a parcel is more than the real item weight, in which case the pricing is based on the volumetric weight. Whatever the case, I always do a precise calculation for each shipment to make sure it's correct. A parcel's volumetric weight is length x width x height (in cm), divided by 5000. Since I know the courier services have cutoff weights of 30kg, I have designed the custom shipping boxes I use to have volumetric weights less than this where possible.
Please do not ask for international items to be underdeclared for Customs, I cannot do that for obvious reasons. I can though split items into more than one parcel where that can make things easier; note thst for complete systems, all the free items are posted separately (this means a slightly higher shipping cost, but it's not possible anymore to reliably include free items in the same parcel).
NB: I do not use economy delivery services such as Evri, they are too slow and not reliable.
Shipping complete systems includes an extra fee to cover the packaging materials. Note that material costs have increased significantly since 2020 (ie. boxes, foam chips, bubblewrap, brown parcel tape, gaffer tape, etc.), as much as 100% in some cases. The fee is as follows:
Indy, ChallengeS: +5 O2, Indigo, Indigo2 and Fuel: +10 Octane and Octane2: +15 Tezro: +25
If necessary I can split items into multiple boxes if that means a lower
total shipping cost. It depends on the box weight/size, destination, etc.
Either way, I always find out which is the best option.
If a faster delivery is required, I can use parcel2go, with the shipping done by UPS, DPD, Fedex or DHL (it varies which is best as service costs fluctuate all the time).
Sometimes RM pricing is such that it makes more sense to use a courier service anyway, eg. when the cost difference is small.
If a faster delivery is required, I can use parcel2go or Interparcel, with the shipping usually done by UPS, DPD, Fedex or DHL (it varies which is best as service costs fluctuate all the time). Courier options are often cheaper and faster than Royal Mail anyway.
Sea-shipping is usually more appropriate for more remote destinations such as South America or Africa, for which the courier charges can be extremely high. Thus, for example, in late 2004 I sent an Indigo2 and two 17" SGI monitors to the University of Urugay, for which the shipping cost by WTA was 435 UKP with full insurance. By comparison, shipping the same consignment by ParcelForce at the time would have cost 912 UKP (TNT would have charged 1500 UKP!). With import taxes taken into account, the University of Uruguay probably saved about 300 UKP by opting for shipping by sea. How this would be done nowadays though, without the use of the WTA, I'm not sure.
Alternatively, if you're in the UK, I can deliver in person if the destination is reachable in reasonable time by train/bus; naturally I would expect all travel costs and any other expenses to be covered, including accomodation if necessary. I've done this several times in the past, the main advantage being the total prevention of transit damage, which these days has become especially relevant for O2s. This notion is not practical though for bulky items like Octane or Fuel, but I can do it for Indigo2 since I have a proper carrybag.