Fox farm is available to me at a local farm supply store. I live in the middle of no where midwest so I dont have a lot of options. Grow big and tiger bloom anyway. They dont carry big bloom, so i ordered it. Some say you need to add some cal/mag at some point if you have deficiencies. I have never had an issue. Might be the local water I dont know. You can get by with just the trio in my experiences just fine.
The same place sells a huge bail of peat moss for like $14 bucks and bags of perilite for like $6. Just mix in the proper ratios and you got some decent stuff on a budget that should fill some containers.