Alright, firstly, that only occurs during serious network congestion, which is rare phenomenon.  Secondly, as a vendor, you're not obligated to exclusively accept Bitcoin.  I don't use Bitcoin for low-value transactions.  Monero, for instance, is significantly more cost-effective. 

Currently, Paypal imposes a $20 chargeback fee in the majority of countries, excluding the extra cost that's included if the situation escalates into a dispute.