I'm glad you brought up your deleted estimates. Let me provide you with some helpful insights.
Estimates don't get autodeleted. However, you can easily retrieve it by checking the Audit log. However, if the transaction was verified as deleted, then you may have to recreate it.
@ArielIRE: Estimates do not get autodeleted. However, the only way to delete it is to do so manually. To ensure that you successfully delete the item, let's take a moment to clear any filters that may be in place while viewing it.
The OP didn't ask how to delete Estimates. Did you read their question?