Hey Sephera,
Welcome to the boards.
Your seamstress was right at quoting that second costume at about 1k, but there are several ways to cut costs and end up with something that looks nice.
The things that you are going to have built are the bodice and the waist cincher. To me, the bodice looks like black leather, with gold piping at all of the edge seams, and chantilly lace along the bust line. It doesn't look like it closes until the bellybutton, so I'd reccomend some good garment tape to ensure that you don't fall out. The bottom has a peplum, and the sleeves are slashed (and piped). The structure and patterning of this piece is where a bulk of that money is going to go.
The bodice looks metal, but you can get that same look with leather (and a great deal more comfort too). You can buy a leather waist cincher at multiple sites. I like the ones at griffin-works, but I don't think they do the shapes you're looking for. What you're looking for is a tooled waist cincher (made out of good saddle leather, not patent or garment leather).
Like
this one. If you get it done at a place that does custom work, you can ask them about using a metallic silver on the garment. Otherwise, get it in a basic color. Then you're going to want some leather finish stripper and some leather dye. You can redye (or get) the corset a light blue or grey, and then get a metallic leather spray and coat it (DO NOT do this pregnant, or near a baby, and either way, you'll want to use a ventillated mask). Then you can re-finish your leather, and voila. It's silvery.
The pants either look velvet or suede. Either way, there's no need to make them from scratch. Find a pair of brown pants that fit you, and then get a bazillion grommetts (not eyelets) You'll want size 00. Grommit down the outer side seams of the pants. Then lace. (I realize that this shows some leg in the picture. If you really want to, you can slit the side seam after you've grommitted and laced. If you have larger thighs, this can make the pants look wonky.
I was going to suggest getting an inexpensive white pirate shirt, but on second look, it looks as though there are just white sleeves and that they are part of the bodice. I'd suggest a basic cotton or linen, and I'd suggest putting the sleeves in with snaps, so that you can take them out and wash them when the pits get stinky (without worrying about washing the leather).
For the boots you have a few options. You can spend upwards of $300 and get some really swanky thigh-high leather pirate boots, or you can spend about $50 and get some thigh high stripper boots, and then fake a cuff at the top. Alternatively,
this place has something in the middle that are priced at about the $100s.
Cloaks are easily bought at the local renn-fair (or on-line renn-fair store), but the cheapest thing to do would be to find an easy cape pattern, and make it yourself. For the trim, find some good 3" trim. Then put it on top of 4" of the same gold fabric used to make the bodice piping. The cloak could be black anything. Avoid velvet if making it yourself, because velvet is extremely high maintenance. Also avoid bright and shiny lining fabrics. You may find good luck with a dark red matte satin. It does not look as though the cloak/cape has a hood or a tie. But since you can't see much of it, it's really up to you. One option is to have it snap to the shoulders of the bodice, but this will really put a lot of pressure on that garment tape that's stopping your boobs from popping out.
And now I have to go to work.