OK, in the interest of serving this community, I'm also going to chime in briefly here. I think this LPP low-temperature plasma energy fusion thing (I know it's not cold fusion but sounds like it) sounds intriguing and would obviously be awesome if the product ever becomes viable. Due diligence notwithstanding, I would consider investing in such a company. That said, I share DaveT's nervousness around the promotion of investment in any private company via this public forum, especially given this suspicious $5,000 minimum you have shared.
To elaborate, I am a moderately experienced private equity investor and venture capitalist. Because of this, I know that investing in a privately-held company is subject to several very important and relevant SEC regulations, particularly the requirements for
Accredited Investors, in addition to the rule regarding a general cap of under 500 shareholders that DaveT already shared. I confess that I too am broadly suspicious of a $5,000 minimum capital contribution in any venture-backed company, but especially one that has purportedly taken on $3million in prior venture capital. Regulation D exemptions are possible, but companies that have been capitalized in the millions of dollars do not usually have the administrative staff necessary to handle taking on large numbers of smaller investors, even if you they all do meet the legal definition of an Accredited Investor. There are some innovative ways of investing that at best offer a "democratized" approach like Kickstarter and AngelList, but one must always be careful that one is not circumventing SEC regulations by investing in any company.
I would urge caution here, because given the descriptions you have shared to date, it would seem like two possibilities exist: either the management of this company is unaware of the SEC laws they may be in violation of, or they are knowingly circumventing them. Either possibility is troubling.
Edit: I see that the company's own investor page actually links to the SEC regulations I posted above, though that doesn't mean they are in full compliance. I remain uneasy about this $5,000 minimum. That just seems odd. Success in private equity investing is about maintaining a measure of shareholder power and resistance to dilution as much as it is about the company's actual business performance. It is disingenuous at best to take $5,000 investments from individuals in this structure, and illegal at worst.
I want to make clear that I have absolutely no judgment here on the worthiness of the company as an investment from a product or business standpoint, simply pointing out that I too have been uneasy about the seemingly odd legal framework here.
Disclosure: I meet the SEC definition of an Accredited Investor and have invested in several private companies in this capacity.