2020 Ram 1500 Laramie 5.7L V8 Repair Estimate & Diagnostic Findings

Looking for a little insight as to what we were just sent by the auto shop. Not sure what is most important, what can potentially be held off, as well as the overall price range. Details below.

Customer Concern
Vehicle was brought in because the check-engine light was on, the truck was shaking, and it was making a strange/unusual noise.
Diagnostic Findings
Engine / Misfire
Technician found a misfire on cylinder 6.
Technician tested the spark plug and ignition coil by switching their positions to determine which component was causing the misfire.
Recommendation: Replace spark plugs.
Exhaust
Technician found a broken/rusted exhaust bolt.
Found a blown-out exhaust center pipe gasket, causing the loud exhaust noise.
Recommendation: Remove and replace intermediate exhaust pipe / exhaust pipe flange gasket.
Heater Core / Coolant
Technician detected a heavy coolant smell inside the vehicle.
Found that the heater core is beginning to leak.
Recommendation: Replace heater core, inlet/outlet tubes, and engine coolant/antifreeze.
Technician considers this a high-priority repair because the leak can continue to worsen.
Rear Brakes
Technician found the rear brake pads are in need of replacement.
Brake pads measured approximately 2 mm, which is considered very low.
Recommendation: Replace rear brake pads and both rear rotors.

Itemized Repair Estimate
1. Exhaust Gasket & Rusted/Broken Bolts
Labor: Remove & Replace Intermediate Exhaust Pipe — Single Exhaust
Labor: 1.50 hrs — $285.59
Part: Exhaust Pipe Flange Gasket
Quantity: 1 — $24.89
Subtotal: $310.48
Estimated Tax: $1.49
Total: $311.97

2. Spark Plugs
Labor: Remove & Replace Spark Plugs
Labor: 3.50 hrs — $666.37
Part: Laser Iridium Spark Plug
Quantity: 16 — $462.24
Subtotal: $1,128.61
Estimated Tax: $27.73
Total: $1,156.34

3. Rear Brake Pads & Rotors
Labor: Remove & Replace Brake Pads — Rear
Labor: 1.00 hr — $159.99
Parts:
Brake Pads — Quantity: 1 — $104.34
Brake Rotors — Quantity: 2 — $384.22
Subtotal: $648.55
Estimated Tax: $29.31
Total: $677.86

4. Heater Core
Labor: Remove & Replace Heater Core
Labor: 8.00 hrs — $1,523.12
Parts:
Heater Core — Quantity: 1 — $152.74
Inlet/Outlet Tubes — Quantity: 2 — $62.00
Engine Coolant / Antifreeze
Subtotal: $1,737.86
Estimated Tax: $12.88
Total: $1,750.74

Estimate Summary
Total Labor: $2,635.07
Total Parts: $1,190.43
Total Fees: $134.51
Subtotal: $3,960.01
Taxes: $74.91
Grand Total: $4,034.92
Balance Due: $4,034.92