You can buy the druid and the hourglasses unupgraded at the bazaar; the druid is instead called "Fallen Elf" and is found with the
cards, while the hourglasses are found in the
section, and are called "Golden Hourglasses" when unupgraded. Unfortunately, the Eternity card is a rare weapon and can only be won from either spinning or from the Oracle. If you can farm T50 successfully, you should get the card eventually; many T50 players either use it or are nice enough to place 6 copies of it in their decks so that you, the player, may earn a copy with a little luck. Scaredgirl's deck works okay when unupgraded, so you can hopefully earn an upgraded card from spinning after defeating a FG and sell it to earn money. Unfortunately, you desperately need the Eternity so you can Rewind your own creatures, or else you WILL deck out.
Remember that if you don't need a card, it's probably a good idea to sell it (unless it's a rare.) You can always buy it later if you have to. The quick money now is usually more useful than the cards in the future.