Doubts in my profile for Marketing PhD

[Brazilian]

Hi! 

I intend to apply for Marketing PhD programs in the US and I hope people here can help me with some doubts I have. 

First, a little about me. 

I'm a Brazilian male, 43 years old, trying to apply at top schools. 

My GRE scores are 165 Verbal / 161 Quant / 4 Analytical Writing. I've not taken the TOEFL yet, but my IELTS overall score is 8.0.

I got a bachelor's in business administration from a university which is considered the best one in Latin America, with a GPA equivalent to 3.0 approximately. I also completed an MBA and a MS (in business), with GPA of about 3.8 in each one. 

I worked for about 20 years as analyst/supervisor/manager at several services companies in Brazil, from small ones to big ones. And then, about 5 years ago, I changed my career and started to teach. I'm currently teaching business classes at an important school in Brazil. 

My experience and academic background are more strongly related to Finance than Marketing, but some of the main challanges I had when working with Finance was to measure Marketing results and to allocate resources to Marketing in a corporate budget. How do I know if Marketing investments are getting adequate returns? How do I decide the amount of money I should provide for each Marketing activity? Those are the kind of questions I had when working for Financial and Marketing departments at a few companies and which directed my research when doing my masters. So, concepts like customer profitability, customer lifetime value and customer equity are of great interest to me. So I want to apply for a Marketing PhD in the US, as I believe that's the best way to study and research about those subjects. 

So, here I my doubts:

1 - Should I retake the GRE? The verbal score is excellent, at 95%. But the Quant is at 79%, which is much less than the 90% typical score expected for top PhD programs. I studied a lot for the GRE and I'm not sure if it is worth investing more time and money to maybe improve my score by a couple of points, or if I my GRE score is good enough so that I should start concentrating in other aspects of my application. 

2 - My undergrad GPA of 3.0 is considered low for a PhD program. However, it is from the best university in my country, from an extremely demanding school where it would be virtually impossible to get an overall GPA score as high as 3.7, for example. I'm planning to explain that in my Statement of Purpose. Am I right if I do that?

3 - It has been very difficult to decide which schools should I apply to. I know a good fit is extremely important. But several schools do not state very much about the research subjects they are most interested in. And among those who do inform about their research priorites, almost all of them include measuring marketing results in a way or another. I also tried to research about schools' faculty, but that is also a lot of work. So, I'm now with a list of almost 30 schools with Marketing PhD programs in US, and hundreds of names of faculty members. This is really overwhelming. And I do not have money to pay the application fee to 30 schools. So, any help to narrow the list down is very welcome at this stage.

Thanks to all in advance.