1) Make a prototype game that is cool and stands out.
2) Contact Sony. The best way is http://www.scedev.net/
Pricing for devkits is typically subject to NDA, though it's fallen quite a bit over the years and generations, as have the requirements for it. In the past, it was necessary to have multiple published games, an established company, legal representation, etc. You know, the usual stuff anybody trying to set up a business will do. Also some more onerous requirements at times, like having a formal office space, website, well defined IP ranges, etc that is a bit trickier for indies. Those requirements may have been relaxed since the last generation.
That said, I would be surprised if they bothered talking to anyone who didn't have at least a handful of game releases out there already. I do feel there's a difference between "indie" and "hobbyist".