Matt (ZPT2012) posted a good question but in most cases the answer will depend very much on where you live. Shipping not to mention import tariffs will vary and the presence or absence of a distributor will also have some influence. The list included:
Pole and Height
Battery and Battery components is almost continent specific because lead acid batteries are classed as hazardous material. Only the expensive AGM batteries are exempt and deemed safe even for airfreight. So now you are limited to whatever type and style is available locally as dictated by distributors or battery factories.
Distributors are able to get better discounts due to sales volume and may pass on some of those savings. however your choice may be limited to what they sell in volume and batteries are not all made equal.
I design electrical systems for off-grid use but sometimes the client lives in some place where they simply cannot get the particular equipment I would normally specify. Then the hunt for a supplier is on. Therein lies another pitfall. Google and perhaps other search engines are now filtered to be specific to the geographical orogin of the searcher so sources on other continents gets filtered out. Someone located in Europe will not necessarily get the same result as I would nor would someone from China looking for the same product. I once had to contact an Italian manufacturer to get the name of their retail sales rep in China in order to get a part number for a part built into a boat destined for use in North America. In some parts of the world importing a product from another country can entail a lot of bureaucratic paper work.
To use wind turbine as an example. In North America only a handful of brand names are considered good reliable products.
There are however a few new products from India which are very price competetive and from all appearances as good or better. Unfortunately there are no distributors and the dealer in California is so far away the cost of shipping from ther to here plus the goverment tax erases most of the savings. Not to mention which delivery could be six to 8 weeks because the distributor does not carry a large inventory.
All of the above applies equally to just about every item on the list. When you ask for hardware specific items it would be helpful if you mention what part of the world you are located in.