For someone like Ryuko with a rather iconic hairstyle I'd recommend dropping the cash on a nice custom wig, unless you plan on doing all the styling yourself. I'm really bad at hairstyling myself so especially for characters with something weird going on I'd probably just end up buying a premade one. I guess her normal hair would really just be a wig with a weft but that'd be the extent of my styling powers.
Noctis' hair looks a little more generic (as far as anime/video game hair goes anyway). People recommend Aarda but I've also had a great wig from Epic Cosplay. I'm not familiar with their shorter/men's wigs though and it'd be nice to know if any one company specializes in those.
For Noctic's weapon you aren't likely to find anything ready made for "a good price." It's a fairly complex sword from what I found online, nothing that couldn't be fudged yourself though following general sword (or gunblade) tutorials. If you've got the time and are trying to save money I'd suggest trying to build one yourself, but if not brace yourself to pay a decent amount for a prop sword like that.
Radcon-'12 : Akicon-'13 : KuroNekoCon-many years ago : Sakuracon-'13, '14, '15, '16 : PAX West-'11, '12, '13, '14, '15, '16 : Rainfurrest '15