Currently on extension of stay ( marriage) cost 1900 baht. Want to exit @ land border, then apply for new non o visa,  next year want to start to apply for retirement visa. Can you see any problems with my plan? 

Unnecessary. You can change from marriage to retirement in-country at the immigration office

As said just have financials available next year and apply for reason of retirement.  No need for a new visa entry.  Immigration may want your wife to be present to insure she is aware of the change.

My current extension expires before I hit 50, 7 month later I’m 50…, I plan on exit on current status then start over, I plan to have some time back in Europe ect so a multi non seems Cost effective. Should be easy enough to exit then start over once I’m 50?

1 hour ago, hank69 said:

My current extension expires before I hit 50, 7 month later I’m 50…, I plan on exit on current status then start over, I plan to have some time back in Europe ect so a multi non seems Cost effective. Should be easy enough to exit then start over once I’m 50?

Be sure you can obtain such visa from country you plan as for retirement most will want to issue non immigrant OA visa which also requires mandated insurance.  I would just get another marriage extension (unless marriage is over) and then travel on a re-entry permit and the following year change to retirement.

3 hours ago, lopburi3 said:

Be sure you can obtain such visa from country you plan as for retirement most will want to issue non immigrant OA visa which also requires mandated insurance.  I would just get another marriage extension (unless marriage is over) and then travel on a re-entry permit and the following year change to retirement.

Good advice to OP not to apply for the 1-year Non Imm O-A Visa with its mandatory Health-Insurance policy.

When you apply for the 90-day Non Imm O (marriage) Visa, be aware that the first time you apply for the 1-year extension that you can ONLY do this for the same reason (in your case: marriage).  You can only change the reason for your 1-year extension to retirement, when you are already on a 1-year marriage extension.  

Also be aware that when after that 1st year of marriage extension and you want to switch to a retirement extension, that in such case you need to meet BOTH the financial conditions for the 1-year marriage extension as well as the financial conditions for the 1-year retirement extension (i.e. having kept +800K/+400K on your personal Thai bank-account during the 12 months preceding your application).

On 8/4/2023 at 8:04 AM, hank69 said:

My current extension expires before I hit 50, 7 month later I’m 50…, I plan on exit on current status then start over, I plan to have some time back in Europe ect so a multi non seems Cost effective. Should be easy enough to exit then start over once I’m 50?

Yes based on the information you provided your plan is sound to get a Non O and then convert to an extension based on Retirement once you are 50. Alternatively you could enter visa exempt and convert to obtain the Non O and extension in Thailand.