Janekom - I think your first sentence is a pretty good example of what we expect from our products: That they're quite reliable, but like anything, not invulnerable to failure, but that failures are uncommon and repairable. We don't publish average lifespan or other statistical information. Whether it's worth the repair or not is ultimately something that each customer needs to decide for themselves.
We don't have an upgrade plan at the moment (we have in the past, we may in the future, but no promises). While we don't have any extended warranties or maintenance plans at the moment, we do have reasonable flat-rate repair fees for all of our products. Those can be seen in the "Out of Warranty Repairs" section of
https://www.dynonavionics.com/warranty-returns.php.