How to get out of Reliance furnace and water heater in a rational way?

We bought our first home in 2022 and our realtor didn't guide us that we should push the sellers to at least buyout the furnace which was rented out from Reliance. Both of these were initially contracted by the original owner with Furnace (includes Furnace, AC, Humidifier, Media Filter and Thermostat) installed in May 2022 and Water Heater in 2020

Here is my current monthly rent breakup for Reliance which I have been paying since possession of property in 2022:

  • Furnace: 145.99 + 13% HST = 164.96
  • Water heater: 22.15 + 13% HST = 25.03

I have paid this rent for 2.5 years already so the total for both inclusive of taxes for 30 months comes out about $5700!

I called Reliance today to check the buyout price for both and here is the breakdown:

  • Water heater: 1199 + tax = 1354
  • Furnace: 9800 + tax = 11074

Total buyout cost: $12428.87

Breakdown spreadsheet

Feeling totally ripped off! I remeber calling them sometime last year and the buyout price they gave me was around ~10k for the furnace, which makes me wonder that this is already a lost deal and buying out would only help me save up my monthly payments for the future since this is already a ripped off price for an already used unit. I don't believe the cost is going to go down by much if I keep paying the rent which means the monthly rent is going through the drain.

Any guidance and option suggestions would be very much appreciated. Thanks