Many Pattaya agents can no longer open bank accounts and some of those that can will only do it as part of a package including the Non-O and extension. Having a Non-O probably allows some of these agents to act for you but it can be done yourself without the added expense of agent fees.
The Canadian Embassy in Bangkok stopped doing the income affidavit earlier this year so that route is not available to you and you must start with the 800k method
FFS Don't panic. If you really need one and you're being asked for 500B to produce one find a cheap nearby hotel for 350 to 400B a night that will do your TM30 and book one night, save yourself a little and your condo bloke gets F All for trying to extort money from you.