With the recent downgrader for all current firmware versions for the PSP released, naturally stocks of Lumines (the game needed for downgrading) will dwindle, whilst the price for the game will skyrocket.
The downgrader is not even a week old, and even now there are some listings for Lumines for $125.
Frankly, it's ridiculous.
The game was released just about near the launch of the PSP - this game is ancient.
So please, if you are desperate for a copy - don't turn to eBay...
First off - try any place that sells PSP games. Anywhere - EB, Big W, Target, Harvey Norman...
Lumines is a damn old game, and that means it will probably be in a bargain bin, or have a 50% off sticker slapped on it.
For the love of God, look in the shops first. You can probably find a copy for as little as $10 - then return it, or try and (hopefully you won't do this like people are doing now) rip off some poor sod on eBay.
second of all - there is no patched version of Lumines.
I cannot stress this enough.
that means, each and every copy of the game that is on this green earth will work with the downgrader.
so don't pay an extra $30 because someone has wrote "exploit version" or have written down the ULES number or whatever on their listing
(e.g. this edition is the "good edition" - whatever you liar, they all work fine) as it doesn't matter what edition of the game it is - original, Greatest Hits(with the red cover) or Platnium - they will work.
UPDATE: Japanese and Korean editions of the game are now supported with the downgrader.
This means that now you may be able to find a bargain shopping internationally for a copy of Lumines - don't just try eBay, try online stores such as PlayAsia or CD-WOW; they may have Lumines in a bargain section or it may be on a special sale (I'm not sure if it would be now, since it has been nearly a month since the downgrader has been released)
None the less...
So! Don't get ripped.
Have fun with homebrew! :D