Buying plants on eBay should be a pleasure, but like everything in life there are some pitfalls.
Many plants are offered on eBay and of those a significant proportion are not what they purport to be. Be certain of the identity of any plant that you purchase and don't end up with an expensive lemon.
Check plants offered against photographs and descriptions, many of which are available in the public domain and easily found on the Web. Ask for the provenance of a plant if you have doubts. This is particularly true of cultivars (cultivated varieties) and other named plants. Cultivars are plants that have been described, named, published and accepted as such by the appropriate registration authority.
Seed of cultivars is often incorrectly offered by vendors. Comparatively few cultivars may be grown from seed as the offspring do not come true. Most cultivars must be vegetatively reproduced (by cuttings, division or in tissue culture) as this is the only method of multiplying the true plant. If a cultivar may be grown from seed this will be stated in the cultivar description, but as already stated this is unusual.
A good example of the "cultivar problem" is Pinguicula 'Weser' A plant of this name is mass cultured by Dutch nurseries and widely retailed in garden-centres throughout Europe and beyond. The same plant is often sold on eBay, as is seed. Unfortunately, the plant is not P. 'Weser' and as a cultivar it may not be grown from seed. The true P. 'Weser' is rare in cultivation and circulates only among collectors.
An unfortunate and increasing trend on eBay is for vendors to add unofficial and wholly unrecognised names to plants. There is one simple reason for this: Named plants attract higher bids!
If the identity of a plant is in doubt or it has been given a spurious name, don't buy it. Reputable and knowledgable growers take pride in the quality of their plants and never intentionally mislead buyers concerning identity.
Shipping live plants from one country to another is most often illegal without obtaining some required documentation. To comply with legal requirements, the absolute minimum documentation required for all plants is a Phytosanitary Certificate. This certifies that plants have been inspected by the appropriate authority (usually the Department of Agriculture or local equivalent) and are free of pests and diseases.
Many critically endangered plants including all of the Nepenthes are CITES (Convention on International Trade in Endangered Species) listed. In addition to a Phytosanitary Certificate, CITES listed plants require both Import and Export Licences to be legally shipped.
Plants shipped without the necessary documentation will be stopped by Customs at the port of entry and destroyed. Attempting to import plants without a Phytosanitary Certificate or where required Import/Export Licences may leave buyers open to prosecution, substantial fines and even jail time.
European Union countries are an exception. The EU is a single market and it is entirely within the law to ship live plants from one EU country to any other EU country, with no requirement for documentation. However, it is entirely outside the law to ship plants from Europe to other parts of the world, or to ship plants into Europe from elsewhere without the appropriate documentation.
Unless it concerns a high value transaction, complying with legal requirements and obtaining the correct documentation is expensive, time consuming and not usually a worthwhile exercise for either buyer or seller. For example, in the UK, DEFRA (Department for Environment Food and Rural Affairs) issue Phytosanitary Certificates for plant export and the current charge for doing so is around £120.00 and a CITES Export Licence £75.00.
Be wary of vendors offering to ship plants worldwide and confirm that all necessary documentation is provided before buying.