"Its rarity value is high," Gibson announced gravely.是什么意思？

"Its rarity value is high," Gibson announced gravely.

“它极为稀罕，”吉布森严肃地宣布。

its

pron. (it的所有格形式)它的，厥；

例句
The government is to accelerate its privatisation programme.
政府将加快其私有化计划的进程。

rarity

n. 稀有，罕见，稀薄，稀少，珍品，罕见的东西；

例句
Motorized wheelchairs are a rarity here...
电动轮椅在这里很罕见。

value

n. 价值，价格，意义，涵义，重要性，（邮票的）面

例句
Cheques can only be accepted up to the value guaranteed on the card...
支票的承兑金额不可高于卡上所担保的数额。

is

vt.& vi. 是（be的三单形式；n. 存在；

例句
Bollinger 'RD' is a rare, highly prized wine.
博林格RD香槟是一种名贵的备受推崇的葡萄酒。

high

adj. 高的，高尚的，崇高的，高音调的，高级的，高等的；adv. （程度等）高地，高价地，奢侈地；n. 高处，高位，[气象学]高气压，高压地带，高水平；

例句
...abnormal heart rhythms and high anxiety levels.
心律不齐和高度焦虑

Gibson

n. <主美>吉布森鸡尾酒；

例句
Mr Gibson is clearly intellectually out of his depth...
吉布森先生显然才智不逮。

announced

v. 宣布（ announce的过去式和过去分词 ），通知，广播，声称；

例句
The subject of the talk is announced a week in advance.
会谈的主题已提前一周宣布。

gravely

adv. 严肃地，庄重地，严重地，沉重地；

例句
But he is denounced - and gravely - by the Citizen and Citizeness Defarge.
不过告发他的 —— 严重告发他的 —— 是公民德伐日夫妇.