Rotax Plug Vs NGK Plug

You do not need to go thru a Rotax dealer for these plugs.  NGK DCPR8E spark plugs are available from many local sources and they are inexpensive.  Here is just one example: https://www.amazon.com/NGK-Standard-Spark-DCPR8E-Plugs/dp/B00YMXAM2W/ref=sr_1_1?crid=2MZ2VBJZMXAK4&keywords=NGK+New+Standard+Spark+Plug+DCPR8E&qid=1685406239&s=automotive&sprefix=ngk+new+standard+spark+plug+dcpr8e%2Cautomotive%2C89&sr=1-1

Yes. it is an old story.
Get out the popcorn and read This, This, and This.
Spoiler Alert: The NGK plugs can be found at almost any auto parts store.
Just don't tell them what you want them for.

Yes - Thanks.  I have a local source for the NGKs.  My question is why are Rotax making us change?  Is it a safety issue?  What's the difference between the $6 NGK and the $30 Rotax plug?

$24 and a manufacturer that's willing to have its product used in airplane engines.

The long story is that NGK did not want to sell plugs to Rotax anymore due to perceived liability issues.
Rotax took the option of having plugs custom manufactured under the Rotax brand and assuming all liabilities.
The limited production run and retail market for the house-branded plugs necessitated a premium price.

It is NOT a safety issue, it is a corporate legal/political issue.
Either plug is just as certified/valid/reliable/safe for use in the engines.