Luxury handbags stand among the many categories of high-value possessions we collateralise as security for our low-interest secured asset loans at peer-to-peer lender Unbolted. We thought it might be interesting to explore how they’ve taken on the status of worthy investment – and how to spot whether, unbeknownst to you, you’ve got one languishing in your loft (there really could be cash in your attic).

To give you an idea of just how valuable these gorgeous fashion items have become, consider this: an anonymous phone bidder paid £146,000 at Christie’s in Hong Kong last year for a 2014 Hermès Birkin bag, complete with Barbie-pink crocodile skin and diamond-studded hardware.

Jane Birkin, icon of style and sophistication in the 1960s, still gets (and donates to charity) £30,000 a year in royalties for the use of her name. That’s because the secondary market in luxury handbags has become huge: the value of the most sought-after items has been climbing on average by 8 per cent a year over the last decade. That’s the same as the annualised returns of the prestigious FTSE All-Share Index. Impressive, no?

According to Fanny Moizant, the co-founder of one of the top designer resale sites, Vestaire Collective, Hermès is king of the castle, courtesy of its superb quality, limited production runs and waiting lists that stretch into several years. But luxury brands such as Louis Vuitton, Chanel and Céline are also selling exceeding well: a Chanel handbag, for example, took the gong for fastest-selling item ever on the Vestaire Collective site, after being snaffled up by an eager buyer in 17 seconds.

Moizant told The Telegraph’s Senior Fashion News & Features Editor, Ellie Pithers:

“You pay 2.8 times today what you would have paid for a Birkin seven years ago - and that's just the retail price.

“There's a huge market for rare bags, and as soon as brands manage the distribution and restrict production, people will pay more. They want rarity, timeless shapes and heritage brands. I think they also like the emotional element of bags named after icons such as Grace Kelly - the bags become brands in themselves."

According to erstwhile Sotheby’s stalwart Kerry Taylor, whereas wealthy buyers from emerging markets such as China and Russia baulk at the prospect of buying second-hand luxury clothing, they don’t mind splashing out big-time on second-hand luxury handbags.

So, are luxury handbags good investments?

Here’s a revealing anecdote from Moizant: a savvy friend of hers bought a bright pink Hermès Kelly bag in a rare skin for her young daughter instead of putting the money into a savings account. Moizant, at the time, was surprised, but not when she heard her friend’s plan. She’s going to leave it for 20 years, protected in a dust bag, “by which point, it will have increased in value as much wine or a luxury flat.”

In Part Two, we’ll help you work out whether you might have one of these lovely items stashed unsuspectingly in your loft. If you have, and you’ve got borrowing needs, you could be eligible for an unbeatable secured asset loan from Unbolted.