Taylor Swift Inc. produces several models of travel bags. An outside supplier has offered to produce the laptop bags for TSI for $$450$ each. TSI needs $600$ bags annually. TSI has provided the following unit costs for its travel bags:

Direct materials $ $80$

Direct labour $90$

Variable overhead $85$

Fixed overhead $(30\%$ avoidable$)120$

Prepare an incremental analysis which shows the effect of the make$-$or$-$buy decision.