i used to wear suits daily for 15 years. i have about 30 of them in my closet. the majority of them are sturdy off the shelf work suits. i have a handful of MTM designer stuff and i have a bunch of bespoke suits that i've picked up in my travels abroad. honestly, the bespoke stuff is the best. you cannot beat a custom fit (assuming you don't gain or lose a lot of weight). and it can be very cheap when getting done abroad as i have.
these days, i can dress casually for work, so my suits gather dust for the most part. i'd say that i put on a suit maybe 3 or 4 times a year now.
Along with
flopticalcube, I'll also echo the bespoke suit experience. It is not just that they sit better, and look far better, more importantly, it is also that with the tyranny of modern fashion (fascism), as defined by the cloth trade, if your body does not conform to what is the approved shape, size and silhouette for your gender (tall, slim and size zero being the preferred options for females, a set or requirements none of which I meet), it is next to impossible to find anything decent which fits, is comfortable and looks well. Personally, I prefer well cut - and comfortable - clothing made from natural fabrics. In recent years, this has meant bespoke tailoring.
Actually, I rarely wore suits when I was a college teacher, more usually, a smart (often tweed) jacket, or a blazer; since then, my work has required more formal attire, not less. Well cut (also bespoke) tweed jackets and blazers are fine, but I have a few very good (bespoke) suits, which I wear in more formal settings.
So, as to how many I currently own, the answer seems to be four good designer suits (light weight wool) and three bespoke suits, of varying weights. One of these is a sort of twill, (in charcoal grey) which means it is both extremely hard-wearing, very forgiving, and yet looks great. It is the one I find I end up wearing most of the time.....