What are the recent requirements and costs for a land visa run to Malaysia from Thailand?

Strongly suggest you ask your question about your wanting to do a BORDER BOUNCE and obtain a new 60 days STAMP as Visa Exempt Entry with an experienced border run service company in your area.

You already have 3 entries into Thailand by air this calendar year. And possible have obtained 30 days extensions 3 times. Which looks like you are living in Thailand with visa exempt entry and extensions.

Be prepared for questions from Thai Immigration Officers upon arrival into Thailand... especially by Air ✈️.

BUT you can also be questioned by Thai Immigration Officers at Thai border crossing entries into Thailand.

Be prepared for DENIED entry.

... Have proof of your flight departing Thailand within the 60 days you are stamped in on arrival.

...Plus have the equivalent of 20,000 Thai baht in CASH AND

...the address of where you will be staying in Thailand.

To show Thai Immigration Officers upon arrival.

Again... with your recent history of staying in Thailand, use an experienced border run service company to take you to the border, bounce and reenter.

They know what you need to do. Will not take you to do a BORDER BOUNCE unless they know you will be successful.

And tell them your passport nation is Canada and recent history of staying in Thailand.

Good Luck 🍀