First off, I agree with Carlinha, 
it's not so much about the number of shoes I buy per month as the cost per pair of CL shoes that I am purchasing. 
I am also of the philosophy, that if a shoe doesn't speak to me, I'm not going to purchase it. Which means that sometimes, like a few other ladies have said here already, that I might go a few months without buying any and then find quite a few that I like within a one month window and do some major splurging. But, overall, I do not purchase "x" amount of shoes per month like clockwork. 
Louboutins: (see above) varies
Other designer shoes: (see above) same principle applies
Other shoes: N/A (I don't really purchase other shoes that are not 'designer' so to speak because I do not find the quality to be nearly as good or comparable which in turn does not make the shoes much of an investment for me. At most, I would usually end up wearing these type of shoes only once and then they would just sit in my closet. After I realized what a waste of money this was and how frivolous I was being about it, I just stopped purchasing them altogether. Although, please understand that I am not trying to snob or look down upon those that do purchase these type of shoes. I firmly believe that if you love something, buy it as long as you know you are going to wear them often, which in my opinion can justify the cost per wear of spending on say a $100 or $3K shoe. But anyways, shoes for me that might fall into this category are: flip flop's, running shoes, hiking boots, slippers, winter house boots (UGG's), rain boot's (Hunter's) etc.
it's not so much about the number of shoes I buy per month as the cost per pair of CL shoes that I am purchasing. I am also of the philosophy, that if a shoe doesn't speak to me, I'm not going to purchase it. Which means that sometimes, like a few other ladies have said here already, that I might go a few months without buying any and then find quite a few that I like within a one month window and do some major splurging. But, overall, I do not purchase "x" amount of shoes per month like clockwork. Louboutins: (see above) varies
Other designer shoes: (see above) same principle applies
Other shoes: N/A (I don't really purchase other shoes that are not 'designer' so to speak because I do not find the quality to be nearly as good or comparable which in turn does not make the shoes much of an investment for me. At most, I would usually end up wearing these type of shoes only once and then they would just sit in my closet. After I realized what a waste of money this was and how frivolous I was being about it, I just stopped purchasing them altogether. Although, please understand that I am not trying to snob or look down upon those that do purchase these type of shoes. I firmly believe that if you love something, buy it as long as you know you are going to wear them often, which in my opinion can justify the cost per wear of spending on say a $100 or $3K shoe. But anyways, shoes for me that might fall into this category are: flip flop's, running shoes, hiking boots, slippers, winter house boots (UGG's), rain boot's (Hunter's) etc.
But I like your idea C of a monthly budget! I just wish I knew the entire season's collection in advance so I could pick which ones I would go after and not buy the ones I don't like as much.
I know some of your pairs are highly coveted!
..depending on how many styles are on my wish list, I may get 3-4 pairs at a time in 1 month. WE all know how popular CLs are these days so if you don't get them quick you might not get them at all..
