Having an old dirty oven is not a reason to throw it out. Some of the ovens I come across cleaning ovens are old and dirty. But also they can be very well made and with a good clean will operate like new.
This oven is a Whirlpool oven and yes it was dirty but it's a solid oven "cooks sponges well" and it was just waiting to be cleaned. Not only would this cost a lot to replace with an oven that is as good quality it's also the best for the environment. Cleaning rather than replacing, lengthens the working life and ultimately prevents landfill, energy used to make new ovens and the use of virgin materials to make new ovens.
So go on give your old oven a chance, give your oven treat and book a clean today.