As far as the OP's question on buying autographs...
That Lockwood site: I'd avoid that. It looks like it either is defunct now, or may not have been legit. Not sure, but my spidey-sense is tingling...
If you really want to buy? Do your homework. Be smart.
Compare prices. Don't just buy the first thing you see.
E-Bay is a massive mine-field and you are more often than not going to get ripped off. There are exceptions, but they are super rare. The only time I'd trust e-bay is if you're buying from a well-known convention company, or rarely sometimes the actors fan-clubs will use e-bay for auction purposes. If it's the actor's club doing it though they'll be linked back to the actors official site and such. Don't just trust because someone claims to be representing the actor.
(oldest, longest running company) uses e-Bay. They also sell right from their site. Again, do your homework and compare prices. But they're one of the very few reliable places. They've been in business 30-35 years and I've seen them having the actors sign stacks of photos for later re-sale at their tables when the autograph lines are done.
Some of the actors - not too many, but some - do sell via their websites. Can't think of whom off the top of my head.
The best way to acquire autographs is in person. But if you're wanting to buy... it can be done. It's not going to be cheap though, and you can't just trust e-Bay or what not. You have to really research.
Following prices are pretty much as is for either in-person or buying from somewhere legit:
Prices can vary, but for say Patrick Stewart you'll pay at least $60-80. Roughly the same on Shatner, Jeri Ryan, Leonard Nimoy, Jolene Blalock. Mulgrew and Brooks usually about $40-60. Scott Bakula is the most expensive at the moment, you'll rarely see him for less than $100 and usually more towards $125.
The most "average" price - which is what you'll pay for 80% of most cast members - is $30-40.
Sometimes, if you find the right place, you could get certain actors who do a large volume of conventions (Bob Picardo, George Takei, Ethan Phillips, Walter Koening) for $15-20.
Deceased actors autographs (which at this point can only be acquired via purchasing) you really have to be careful where you buy from and you'll be paying a good amount for them. Jimmy Doohan is going to be cheapest of those who've passed on, usually $50-75. DeForest Kelley is going to set you back $200-300. Majel Barrett about $50 - I think Roddenberry.com even has some, not sure.
These actors are more likely to be counterfeit though, since they're gone and people are more anxious to acquire such, so be more careful.
Gene Roddenberry, you'll need to be an expert to find a legit one and once you do, you'll be paying $400 and up, minimum, if you're lucky
. He's been gone 20+ years and no one sells them unless the owner has passed and the estate sells their collection, frankly.
Any of the nuCast... they're rare. John Cho and Anton Yelchin I think have each done one or two shows, Zach Quinto did one or two, but most autographs of his you'll find are from "Heroes". Pine, Saldana, Pegg, Urban... never done conventions. Anything you buy is going to be coming from someone whose business is such, and in those cases it's all about vetting them.
I can't repeat this enough: research and trust no one when buying. You can't just google "buy autographs" click a link and do so. You have to really look into a company if you're buying from them. Their policies, their business history, who they're established with (there are organizations most of the legit ones belong to) and... really, it's a gamble. But one that, if you're smart and thorough about, you can minimize the risks of.
Luckily, Star Trek autographs are one of the few fields where acquiring such isn't terribly hard, so the need to fake them isn't as great as other fields of interest. That said, it's also easier for you to get them in person for Trek, so if you can? Do that first.