gotta slightly disagree with the above mentioned "head out now if you are worried about cost".
granted, this is pretty much a rich mans hobby, there ARE things and replicas made that aren't an arm and a leg. plus you can always build your own stuff from hardware pieces like plumbing tubes, pipes, etc.
the goal that needs to be set for this hobby is just understanding and budget. if you know from the outset that a replica of a rock will run you about 40 bucks, then you are ok. it might seem dumb to you, but that rock could be a replica piece of amber for a jurassic park fan, or a green rock for a smallville fan.
if you understand that a basic vader costume that looks remotely replica or prop related will run you several hundred dollars (talking about the rubies supreme), then you are off to a great start.
99% of the work, projects or just stuff you find online that are replicas or bits and pieces you use to build up kits or just small discs used for random things all have to be made, and generally in someones spare time. not everything used in every movie is something you can head off to wal mart and buy. making these takes time and effort, and thats why 3 dollars worth of resin can run you 50$, because you are paying the persons time and talent fees for making that particular part. its why $2 worth of aluminum may run you almost 100 bucks. the person making those pieces has to not only cover whats worth thier time and money, but the wear and tear on thier equipment, and the cost of the supplies anyway. it all adds up pretty fast.
as long as you keep your expectations normal and reasonable, then you can find a nitch in the hobby to go with, and it sounds like you already are going for the "self built" area anyway. i have seen BEAUTIFUL hardware sabers that match anything coming off the MR product line, made with maybe 30$ worth of various hardware parts. again, talent plays a big big part in this hobby. check out what chewie15 can do with about 50 bucks worth of oil based clay, or what playskool can do with a few bucks worth of pvc pipe and misc stuff he got from lowes.
the hobby can be very very expensive. if you dont realize that from the outset, you are setting yourself up for some serious serious disappointment in the long run.
personally, im not made of cash, and i have been in the hobby for years. i dont own many "high ended" pieces, but over the years its become less about the hobby itself and more about the friendships made in the hobby. just because i dont have the money for a monet or an original picasso doesnt mean i cant enjoy looking at it as much as the next guy. take the constantine brass knuckles thread. that is a perfect example of how something goes from idea to virtually completed replica. i may get one, it might be out of my price range, i dunno yet. it doesnt mean i dont appreciate the effort that went into it, and the talent it took to make it happen.
the best advice i can offer for you is just to sit back, think about what you want to spend your cash on, and what your money is worth to you. if that 300 bucks for the han blaster seems to be worth it to you, grab it, build it and enjoy it. if it seems kinda strange to spend that kinda cash, try looking for a resin replica of one and put it together and paint it. if the kits price seems outrageous to you, then you may want to rethink the hobby.
a platinum card isnt required to be in the hobby, but lord it helps sometimes :lol
hope you enjoy the stay
chris