Apple is a company that makes active money out of secrecy. This week's iPhone launch is surrounded by plenty of rumours and some surprisingly solid detail, and that's exactly the way that Apple likes it, because it's all free publicity for one of the world's biggest companies.

The one detail we can be assured of is that the new iPhone models won't be cheap. Apple doesn't do cheap. It's simply not in Apple's DNA to even consider what the word "cheap" might mean, because it considers itself a luxury brand in the company of brands such as Rolex or Ferrari.

Apple actively wants an iPhone to be an aspirational luxury product, and it charges accordingly. While some rumours put the price of the best new iPhones steering towards a wallet-alarming $2000, even the entry-level new models are likely to tip the scales over $1000 outright. That's a lot of money to lay down on a smartphone, but iPhone buyers are typically loyal to the brand.

Fortunately, if that describes you, the chances are good that one way to lessen the sting of buying a new iPhone is right in the palm of your hand. One beneficial factor to staying faithful to the Apple brand is that iPhones tend to retain their value for far longer than their Android cousins, and that means if you're looking to trade up to a new model, there can be some significant value to be realised from your existing handset.

That doesn't mean you should rush into taking the first offer you get, however, because the differences in ease of approach and especially the funds you're likely to realise can be substantial.

As an example, Apple offers its own "trade-up" scheme, run through its stores or online, where you trade in your existing handset for Apple Store credit to be put against a new phone. It's actually run by a third-party company, and the prices you'll get are pretty appalling. At the time of writing there's no listed price for an iPhone 7, but a 128GB iPhone 6s in perfect working order will net you a paltry $210. Given Apple will charge you just $1.05 less to repair the screen on that exact model, it's a terrible deal.

Telcos, too, will offer you a range of trade-ins. They all have their own "new phone" style deals, where you recontract for a further 24 months and get a new handset, but there you're handing over a working phone that you've made up to a year's worth of repayments on, and getting absolutely nothing in return for it. Economically, that's a poor deal.

All three major telcos also offer the option to trade in a phone you fully own for mobile bill credit, which will at least realise you some funds towards your phone bill, if not actually your new handset. Although it's worth noting that Telstra uses the exact same third-party seller as Apple, with the same low offered prices.

You could opt to go for a second-hand dealer or pawnbroker, although there you're likely to get wildly variable pricing depending not only on the condition of your phone, but also the whims of the merchant involved.

The online equivalents are the many businesses that specialise in buying secondhand mobile phones under brands like Mobile Monster, Cashaphone or Mazuma Mobile, to name but a few. There you're likely to see a better result with relatively little fuss, but it's worth checking multiple sellers, because prices can vary a lot. As an example, I was quoted between $340 up to $530 for an iPhone 6s 128GB, and between $510 and $720 for an iPhone 7 128GB from a variety of mobile resellers when testing recently. That's a significant difference that you could put towards a new iPhone for the exact same handset.

As my older relatives used to endlessly say, if you want a job done right, do it yourself, and that applies to iPhone sales as well, because the best realised prices you're likely to see are by selling it yourself, whether in person or online. Gumtree's online price checker suggests that iPhone 7 models typically sell for $859 through its service, while parent company eBay has completed listings for iPhones ranging between $700-$1000, which suggests that there are buyers.

Of course, selling that way involves more work and more risk on your part, because you've got to either mail your phone to a stranger (and hope they don't try to keep it and reverse the payment), or meet someone while keeping your goods and person secure. Still, if you hanker after the latest and greatest and want to pay the least for it, it's clearly the way to go.

Alex Kidman is the tech & telco editor at finder.com.au.