Just throwing out another alternative option in case it's one that interests you.
Jhoira, Weatherlight Captain is a storm deck that can be built very budget friendly.
Artifact cost reducers and 0-2 costed artifacts are plentiful and for the most part can be picked up for very little real world money.
I literally smooshed a deck together that was made of a few key pieces and every cheap artifact I owned and it worked brilliantly. The good thing about it is that it doesn't matter what the artifacts do, you only care about drawing more cards so you can play more artifacts to draw more cards to play more artifacts.
Then, of course, you can actually tune it and put in some effort and choose your artifacts with care and attention.
Tormod's Crypt,
Claws of Gix,
Spellbook etc.
I appreciate you said that you wanted go down the instant/sorcery route, which is totally fair enough, but thought I'd highlight this as an option as it's something I have personal experience with building on a budget and can vouch for it's effectiveness.
Also, full disclaimer, I fucking hate playing that deck. I was super excited when I built it and my god is the turn you go off a pain in the ass. Spending 10 minutes to cast 50 spells and still not being 100% sure if you're going to win until it happens while your friends sit there and
wonder why they bothered turning up. Eurgh. There is a lot to be said for the efficiency of infinite combos. "I demonstrate my loop. Can anyone stop it? No? Cool. I win. Let's play again" sometimes feels better than "I think I win, but let's take 20 minutes to find out".