The loan value is not the retail price of your item. It is a slice of what the item would reliably resell for, which is why two similar pieces can produce different offers. Condition, authenticity, documentation and current demand all move the number, and any decent pawnbroker will say which of those moved yours.
Redemption is simple enough. Inside 30 days you repay the principal plus the agreed interest and take the item home. If the month is tight you can pay the interest to extend instead of losing the collateral. If you decide you would rather sell than redeem, raise that before the loan matures, not after.