If you have been okay with 20-30 mgs of Methadone and the clinic wants to start you off on a higher dose, they are trying to fuck you over. Think about it...why the hell would you ever take more? If anything they should try to start and taper you down or start using suboxone to get off the methadone. I've been in your shoes, and I would recommend getting health insurance and getting them to pay for your Suboxone prescription.
Try to find a good clinic, one that actually seems to want to help you. Tell them you want to get off pills asap. Methadone is really hard to get off of, and so is Suboxone, but from personal experience, I think it goes Full Agonist Opiates, then methadone then short tapered suboxone.
I may be wrong, there are a lot more experienced users on this website. I was unable to stand the suboxone withdrawals and relapsed, so I have no room to talk. But I went back to methadone, and for me, the withdrawals were more severe and longer.