Card prices probably basically follow supply and demand - the reason a given card costs a given amount is because players are in general willing to pay that price. If demand goes up, and supply stays the same, the price goes up. If people stop wanting it, nobody can sell it at that high price, so the price has to go down in order to be sold.
The only way to bring pricing down is to not buy cards that you think are too expensive. As mASTERsELF said, allowing proxies is one way to make that easier.
Also, there is no sign that Magic is dying out - it in fact has been rapidly growing for years.
Planar Catastrophe5WUBRG
Sorcery
Sacrifice all permanents. Until the beginning of your next upkeep, all spells have flash, and each player may cast spells without paying their mana costs.
Smug Genius2U
Creature - Human Wizard
Taunt (At least one creature attacks you each combat if able for each creature with taunt you control.)
When Smug Genius comes into play, you may look at target player's hand. "Everybody's stupid but me. Idiot."
1/2
Enraging DiatribeRU
Sorcery
Creatures you control gain Taunt until the beginning of your next upkeep. "Look at your pathetic army. You know, armies like yours are the root of all the problems we're having. Look at you, just standing there. I can't believe you have the gall to...[etc]"
Rage Spring1RRR
Enchantment
Creatures you control get +2/+0.
Creatures your opponents' control have Taunt.
Jeering Tree2G
Creature - Treefolk
Taunt "I've seen Phyrexians prettier than you."
0/4
I really like the Thievery idea! I think it may be a bit too powerful for the cost. Maybe make it a 1/1 and/or increase it's mana cost?
Adorable KittyWG
Creature - Cat
Prevent all combat damage that would be dealt to or dealt by Adorable Kitty.
You may choose not to untap Adorable Kitty during your untap step. t: Target non-artifact creature can't attack, block, or use activated abilities as long as Adorable Kitty remains tapped. "I can't, there's a cat on my lap."
0/1
The only way to bring pricing down is to not buy cards that you think are too expensive. As mASTERsELF said, allowing proxies is one way to make that easier.
Also, there is no sign that Magic is dying out - it in fact has been rapidly growing for years.
Sorcery
Sacrifice all permanents. Until the beginning of your next upkeep, all spells have flash, and each player may cast spells without paying their mana costs.
Creature - Human Wizard
Taunt (At least one creature attacks you each combat if able for each creature with taunt you control.)
When Smug Genius comes into play, you may look at target player's hand.
"Everybody's stupid but me. Idiot."
1/2
Enraging Diatribe RU
Sorcery
Creatures you control gain Taunt until the beginning of your next upkeep.
"Look at your pathetic army. You know, armies like yours are the root of all the problems we're having. Look at you, just standing there. I can't believe you have the gall to...[etc]"
Rage Spring 1RRR
Enchantment
Creatures you control get +2/+0.
Creatures your opponents' control have Taunt.
Jeering Tree 2G
Creature - Treefolk
Taunt
"I've seen Phyrexians prettier than you."
0/4
----
Next: Persuade and/or Coerce
Adorable KittyWG
Creature - Cat
Prevent all combat damage that would be dealt to or dealt by Adorable Kitty.
You may choose not to untap Adorable Kitty during your untap step.
t: Target non-artifact creature can't attack, block, or use activated abilities as long as Adorable Kitty remains tapped.
"I can't, there's a cat on my lap."
0/1