Illegal Voxengo suppliers - Q&A

Definitely, no.  Currently, Aleksey Vaneev (the owner of Voxengo.com and exclusive rights to the Voxengo software) has no official re-sellers beside DVD Lernkurs (Germany), magic multi media GmbH, DontCrac[k], Prime Plugins, JRR Shop, Music Marketing, Inc., Plugivery and its partners (KVRAudio, Thomann, etc.).  Previously, RegSoft.com, Inc., 2Checkout.com, Inc., Plugin Boutique, Splice, and Cakewalk, Inc. were officially re-selling Voxengo plug-ins.

A legitimate Voxengo customer may decide to re-sell their licenses to another customer: this is legal as long as license transfer is registered via the Voxengo web site.  You may be safe to purchase a Voxengo product license such way.  At the end of the transaction you will see the product key that comes with the license at the User Area of the Voxengo web site (license transfers are automated and do not require Voxengo staff's involvement).

It should be also noted that you should be careful when purchasing Voxengo licenses on eBay: never buy a license that is advertised as "Not For Resale" license as such licenses can't be legitimately sold.