Recommendation Against Repair
After checking over your [product] thoroughly, my opinion is that it would be inadvisable to make the necessary repairs due to [reason].
The [product] requires [list items] plus several other parts. My estimate for parts and labor is approximately $ [dollar amount] and you would still have a [year] model.
Please advise me as to what you would like me to do at this point. I can be reached at [telephone]. Thank you.