For $7 ($5+2), the card is safe, but the equip is destroyed. For $2 more, you can keep both. For equips with multiple cards (let's just say, for example, a +10 TTHH mace), it's $5 + $2 for any card you want to keep. So:
If you wanted to keep just the T's, but nothing else (2 of the cards): $9
All 4 cards: $13
All 4 cards & the equip: $15
And so on