I use a commercial mix a greenhouse grower nearby sells me by way of compressed bales- 3.8 cubic feet for $25. It is about 80% peat, but also contains perlite, vermiculite, limestone, macro and trace nutrients and a wetting agent.
Often it is referred to as promix or peat-lite mix. The one I use is an all purpose growing mix. It's all I need from the starter flat to 15 gallon containers.
To me it's not worth the effort to make my own mix for vegetables although I do so for my nursery trees, for which I use a heavier mix.
I get better results than if I use big box products and it is much cheaper.