Remember the ONLY official web site to download LimeWire:
http://www.limewire.com/
(also
http://www.limewire.org/ for the open-sourced developement versions)
The official package is fully open-sourced, and subject to the GPL licence requirement: this means that a derivated work is possible according to the licence, but the GPL requirement still applies, and LimeWire clones MUST provide their sources as well, along with a copy of the GPL licence and information about how to get the sources of their clone. The GPL licence also requires that the copyright notice must be kept. Scammers that steal the sources to sell a product under their own licence are infringing the GPL licence, and they steal your money.
Also you won't get any support from this scammers that don't even show their official organisation name and street address.
Compare this to what the LimeWire web site displays for you: a physical address in NYC, USA, and people names (and their photos!). Nobody should ever buy anything on the Internet without being able to identify precisely who is the reseller.
Also some credit card processors should really be avoided for any online transaction: IBILLCS is a wellknown heaven for scammers and porn site spammers that steal your money: their identity verification is VERY weak (a "seller" can create an account with a fake identity in a few minutes with them, and they will immediately start collecting money; IBILLCS will refund those that complain, without taking any action against the scammer, that will continue to collect money). Serious credit card processors consider security more scrupulously and assist users legally: your national street banks, PayPal/eBay...
There's nothing that LimeWire can do about these scammers if you have been stolen, except publishing information about known thieves, and learning you how to use Internet more securely, notably when performing online transactions. Users should know that thieves exist everywhere on the Internet under fake identities. Those that receive hundreds of spam each day from around the world know that fact. On the Internet you NEED to be PARANOID and not trust anyone for which you can't even verify basic identity information.
LimeWire will also inform you about what you can do with the software and offers you a FREE try of the fully functional software, with the Basic version. If the Basic version works for you, be confident that the Pro version will also work for you; after your trial, that LimeWire thinks will be conclusive for you, you can then opt to support the LimeWire development project by buying a LimeWire Pro licence.
Note that the LimeWire Pro licence is NOT limited in time (only the free upgrade and free support which are exclusive to the Pro licence, are limited in time).
All serious Gnutella servent vendors offer you a free try of their software, even if they sell you licences to a Pro version to cover their development costs (this includes LimeWire.com, BearShare.com, GTKG), and they also have extensive online support areas, forums, and their developers are present in these forums, or in the Gnutella Developers Forum (GDF) on Yahoo Groups, where they discuss the protocol and help each other to detect possible bugs and quirks, or enhancements, and where they publish their own working or experimental specifications, to maximize interoperability.