Hi there and welcome
It's lovely that you're looking into what's best for your piggies
One of the most economical bedding that you can buy is fleece, which may sound odd as it's very untraditional, but it's becoming a fast favourite amongst piggy-keepers
There are various ways to use fleece. If you are handy with a sewing machine you can make a fleece quilt (top layer of fleece, middle layer of 6-8 oz polyester wadding, bottom layer of fleece). Other people prefer to have an absorbent layer of something (e.g. towels) under a single sheet of fleece
To make the most of the fleece bedding it's best to have a hay tray, like a cat litter tray or a potting tray, filled with a more traditional disposable bedding for the messy things, I.e. the food bowl and the hay.
Piggies living on fleece will often prefer to pee on the traditional bedding, and thus leaving the fleece fresher for longer before you have to wash it. Also keeping the hay separate maked brushing the fleece down easier to do.
To care for fleece you brush it down as mentioned, wash without softener at 40 degrees and line dry. It dries very quickly, even as a quilt with the wadding
My favourite disposable bedding is Fitch - it's paper based and economical at £22 for 20kg. It's not dusty and kind on the lungs and absorbs liquids well. I just find it easy to scoop out the messy bits and replace, inbetween full clean-outs
I'm sure others will post their favourites, and we all have our preferences and reasons behind them.
Sometimes we start off on one thing and readjust to suit ourselves, our routines and our piggies