Commercial family history magazines operate in a niche market. Nobody is forced to buy them.
Unlike society periodicals, that come as a benefit of membership in an organization which provides other services you perhaps value more, the commercial magazines live and die, and several have died in the past couple of years, based on how well they meet client needs.
Your need for a magazine primarily depends on your family history. Only your can evaluate which magazine, if any, is best for you.
Below is a basic comparison of several newsstand magazines focusing on cost, excluding point of sale added taxes. It is most useful for magazines competing in the same market, with similar cost structures, so the North American and UK based magazines are separated.
North American based
Family Chronicle and Internet Genealogy http://www.familychronicle.com/ and http://internet-genealogy.com/
These are Canada-based publications catering to an integrated Canada/US market. The April and May issues each contain 56 pages, 43% of which are in colour, for a newsstand price of $6.95. The cost is 12.3 cents per page, or if you exclude the 16 pages of ads, 17.4 cents per page.
Family Tree Magazine (US) http://www.familytreemagazine.com/
Caters primarily to the US market. The May 2011 issue contains 74 full colour pages and a Canadian cover price of $8.99. That's 12.1 cents per page, and excluding 14 pages of ads, 15 cents per page.
The UK based magazines below use an ISO standard A4 page size which is 3% larger than the North American 8.5" by 11" standard.
BBC Who Do You Think You Are? http://www.whodoyouthinkyouaremagazine.com/
This magazine catering to the UK market is the longest established and likely has the largest international circulation. Based on the March 2011 issue which has 124 pages, 100% in colour, and a newsstand price of £4.60 = $7.35, cost is 5.9 cents per page, or if you exclude the 26 pages of ads, 7.5 cents per page. This issue also has a cover CD which boasts free records worth £60.
Your Family History http://www.your-familyhistory.com/
The March 2011 issue of this magazine, number 12, which commenced publication in 2010 has 76 pages, 100% in colour, with a newsstand price of £4.25 = $6.79. That's 8.9 cents per page, 10.8 cents per page excluding 13 pages of ads.
My ideal magazine would help with my research interest in England and Wales, and cover developments which don't depend on ancestral background (software, social networks). The magazines that cater to that need are published in the UK. If found on a Canadian newsstand the price is typically doubled or even tripled. Exorbitant surcharges are made for overseas subscriptions, something that could be circumvented by offering electronic versions. UK magazine publishers are missing out on what could be an attractive market.