Are you using the blanket for sleeping or are you using it for sitting around during the day?

It is generally better to use a warm blanket for sleeping than an electric blanket.

My father used an electric blanket in the last years of his life. The store that sold the blankets warned us to turn the blanket off before he went to sleep because electric blankets can affect one's metabolism.

Being baked by electric coils all night long is not a good thing. It messes with the metabolism.

Old electric blankets have been known to catch bedding on fire.

Local stores in the US carry affordable sleeping bags and blankets rated to -20°C. I've slept outside on nights well below freezing with a good sleeping bag.

The new artificial fleece blankets are wonderful. The room where I sleep drops to 45°F (7° celsius) every night.

I use an artificial-fleece blanket and stay warm.

I prefer the fleece blanket to the sleeping bag as it is easier to wash.

As for heating a room on a budget. I like to bake bread and an occasional pie.