Is $6,820 to replace attic insulation with fiberglass a fair price?

I’m planning an attic insulation upgrade for my 1969 bungalow in Calgary, Alberta (climate zone 4). Right now the attic has about 4 inches of old wood shavings. I just finished a 6-month reno with lots of new pot lights, so I’ll be making sure each one gets properly sealed before the new insulation goes in. I’ve done a lot of reading, but I keep seeing conflicting opinions on fiberglass versus cellulose. Fiberglass doesn’t absorb moisture but can let air move through, while cellulose settles over time but has a higher R-value per inch and fills gaps better. Since I’d be topping up to R-50 either way, I'm unsure if the choice really matters in practice. I'm curious about the settling aspect of cellulose.