They won’t issue you a visa while you have a visa if you left without a re entry permit it’ll be cancelled on arrival if your eligible you may get a 60 day exempt stamp
You can not extend a 90 day visa for 30 days if you have a 90 day visa you may have a tourist visa which is valid for 90 days which you would be stamped in for 60 days this can be extended by 30 days
45-50,000 for everything non-o,extension ,bank account and re entry permit have two friends just paid 46,000 baht each and been waiting 6 weeks it’s getting tough to use an agent