Why does it say the inventory is not available?

Steam only shares an inventory that is set to Public. The owner can change it under Steam - Edit Profile - Privacy Settings - Inventory. It can also mean the account holds no Rust skins.

How are the skins priced?

At the same canonical price the whole wiki uses: Steam's lowest sell order for the skin, or the highest buy order when nothing is listed. Skins with no Steam market listing show as unpriced and count as $0.

How fresh is the data?

A fresh read from Steam is kept for 24 hours; the Reload link forces a new read. Prices are always today's.

Is the Rust inventory value accurate?

It is what the inventory is worth on the Steam Community Market right now, which is what almost everyone means by inventory value. What you would actually receive in a sale is lower: Steam takes roughly a 15% fee on every market sale, and thinly traded skins can take a long time to sell at the listed price.

Do I need to log in or send a trade offer?

No. Everything is read from public Steam data, so there is no login, no API key and no trade URL - which is also why you can check anyone's inventory, not just your own. It is free with no cap.

Can I see what an inventory looked like before?

Yes. Every day an inventory is checked, a snapshot of its items and that day's prices is saved; pick a date on the result page to view it. The value chart also has longer ranges and a custom date range.

Can I use this from code?

Yes - the rust.wiki API exposes the same lookup at /api/v1/inventory/{steamid} with an API key.

Rust 库存价值计算器

粘贴 Steam 个人资料链接、自定义 URL 名称或 SteamID64，即可按本百科其他部分使用的同一套 Steam 实时价格，为该账号的 Rust 皮肤估值。库存必须在 Steam 上设为公开。免费，无需登录，无需交易报价。

指南： Steam 交易限制：为什么无法交易以及如何查询

已查询的库存

58,658

已查询的总价值

$18,870,006.26

最有价值的 Rust 库存

第 274 页，共 2933 页

#	玩家	物品	价值
5461	Feelz	177	$764.34
5462	Nerf	362	$764.33
5463	snuki	91	$764.29
5464	Shlieee	325	$764.18
5465	vading	171	$764.12
5466	Thérèse	250	$763.72
5467	Zlinky	77	$763.69
5468	VipenTV	216	$763.52
5469	D22 Navara	150	$763.52
5470	Kugo	354	$763.29
5471	Jayrod	208	$763.22
5472	Rakki	189	$763.00
5473	Procedural Map33	271	$762.98
5474	munchie	285	$762.93
5475	Walen	332	$762.76
5476	Shreko	394	$762.41
5477	Australian_Satan	98	$762.37
5478	Dammen	366	$762.12
5479	Teddy	417	$762.07
5480	Projectile Invalid	94	$762.02