And yes, depending upon where you live, access to magazines can be a little challenging, especially if your local newsagent makes more money from stocking calendars for next year, rather than magazines!
Anyway, I've come across a website called Magazine Cafe - it is jointly owned by Conde Nast and National Magazine Distributors Limited (known as COMAG) which primarily offers subscriptions to various magazines, however, it does also offer (for some, though not all) the option to buy single issues - ideal if you want to undertake a market analysis.
Despite being a UK-based website, many of the magazines available are international, so it might be worth your while just spending fifteen minutes browsing the site to see what you can find!
And don't forget, if you have a computer (how are you reading this otherwise?) you can always purchase digital copies of magazines, through the Zinio website (search for 'Zinio' and your own country, to be taken to the correct Zinio site) and in the UK Pocketmags is useful resource too, offering access to International magazines.