My
: putting in $450 is worth it - especially as reliable as you say the Jeep has been for you - even if other things go away down the road. You said it yourself, you're an avid oil changer and these engines go 400k.
My brother always says, "You either make repairs, or make payments, and hopefully not both". In this case it seems there's nothing else wrong, so keeping it running is a good option IMHO.