Mirvish seasons tickets for over two decades and have received as much as 40-60% off the base prices. We were watching up to 7 shows for the price of separately buying tickets to 2 or 3 of them. Following our strategy of seeing more for less, our subscription falls in the lowest price range, although I've had this subscription for so long that I now hold some of the best seats within this section. For the 2012-13 season, we paid $179 for 6 musicals (love musicals!!). So I'll be watching The Book of Mormon for under $30. The Mirvish subscription is one of the most flexible as it allows free ticket exchanges up to 48 hours before the show.
Toronto Symphony Orchestra Plays James Bond for $29 per seat. This option was not available for the same show later that evening. You need to be careful trying this with longer running shows, because often the matinee performance will feature the understudy as opposed to the star. Some shows offer preview performances at a lower price. You get a discount for agreeing to see a show before hearing the reviews. The Stratford Festival usually has a preview session for their shows early in the season.
One great tip I've discovered is that you can sometimes save most or all the online or over the phone service charges and extra fees by purchasing your tickets in person directly from box office, as opposed to paying for the convenience of buying online or over the phone. I have had savings of over $20 for two tickets by going this route.
If you are willing to wait for a sale and possibly miss watching a show, there are many opportunities to score cheaper tickets. Some theatres such as Mirvish offer same-day, limited "rush seats" or promote ticket deals towards the end of a show's run. Group discount websites like Groupon or TeamBuy occasionally offer up theatre deals, especially for smaller or less popular shows that need the attendance boost.
The shows at smaller venues like the Factory Theatre, Tarragon, Lower Ossington, Hart House Theatre, etc. are usually offered at a much lower price and sometimes even have a "Pay What You Can" day. I often prefer the lesser known, more intimate shows over the big blockbusters that are sometimes overhyped. One of my favourite shows from a few years back was "Ride the Cyclone", performed at the Theatre Passe Mureille. I enjoyed this smart, dark comedy of a musical as much as I did watching War Horse and much more than The Wizard of Oz.
Once a year in July, we go for really small, sometimes experimental works by attending the Toronto Fringe Festival. For a 12 day span, you can watch 45-90 minute performances for $10-$12, in all sorts of venues ranging from small theatres to wacky locations like a bar, a bra shop or a traveling bus. You take your chances and often get what you pay for. But every once in a while, a gem such as The Drowsy Chaperone or Kim's Convenience shows up at Fringe, becomes the theatre darling of the year and gets picked up by mainstream theatres for a professional run.