I have been wandering through many forums, but I don’t have an up to date answer.

I am Australian.

If I enter by air through BKK I get a 30 day visa exception, how long can I extend that out for if I go to a domestic immigration office and pay the 1900bht?

What if I cross via land, 15days and how long can that be extended for?

Can I still get a double entry 60day (extended by 30 for 1900bht) tourist visa from Vientiane these days?

I am not looking being there a real long time, but I do wish to explore, hang out, and it would be nice to rent a room for 6 months so I have a base in Bangkok to keep my stuff ‘safe’.

6 months is what I am kind of thinking, and I want to visit Laos when I go to northern Thailand.

Best option is to go to vientiane and get the double entry tourist visa.

Visa exempt entries can only be extended by 7 days, for which you have to show proof of onward travel within those 7 days.

For visa exempt entries you can only get a 7 day extension it does not matter if was by land or air.

Yes you can still get 2 entry tourist visas in Vientiane that can be extended fpr 30 days.

You could get your tourist visa before leaving Australia. You can get a 3 entry there that would give you almost 9 months without getting a new vsia.

Agree with Joe, misread you were already in BKK. get a 3x tourist visa from Australia, this will save you possible troubles with the airline also, as without a visa you would need to have proof of onward travel within 30 days. Some airlines will refuse you without that or a visa.