I spend most of my friday nights during high school playing MTG. I started playing when beta was released, quit sometime recently after Meridian block. Used to play competitively in tournaments too.
By far my favorite deck I ever made was an academy rector based deck right after oath of druids was banned in extended. It was amazingly fun and I threw it together the night before the tournament. It did really well!
Some days I miss playing, then I look at what it costs these days to build a decent competitive deck and I don't miss it anymore!
There are ways to make the game less expensive, but I'm speaking as a limited player. I stopped playing constructed (extended) after the Onslaught block. As for official tournaments, now I only play prereleases and sometimes drafts. I try to sell the most expensive cards and keep the rest in my collection. I use my collection to play drafts with my friends and that's my main way of playing MtG - it doesn't cost any more money and I take the most value from my cards. :)
If you price out the top 5-6 decks from the world tour, the average price is well over a grand
there's not many 'budget' decks anymore that are competitive at a tournament level. Used to be able to get away with a deck full of common/uncommon zombies/goblins and do relatively well. We had a person play 8 total rares in a goblin deck and go 5-3 at a regional tournament. I think his deck had maybe $100 worth of cards in it.
Definitely can't do that anymore, the metagame doesn't allow for it.
Drafting is relatively inexpensive, but I was never a real big fan of it. Too unpredictable for my liking.
Constructed is quite expensive - I won't argue with that. :)
Pauper (commons only) is a cheap constructed format, but it isn't well supported by Wizards of the Coast. There's also Standard - the average price of the deck that won 2016 World Championship in the format is $257.93, as you can see here:
http://magic.tcgplayer.com/db/deck.asp?deck_id=1269660
The average price of the most expensive deck from the top 8 is $399.96:
http://magic.tcgplayer.com/db/deck.asp?deck_id=1269658