WP User Query with meta queries

I'm having some problems when comparing integer values '>=' or '=' with meta_queries with the WP_USER_QUERY.

Let say I've stored the following meta keys with the meta values below:

meta_key            meta_value

type                type1     
status              active
location            London
min_price           10000
max_price           20000

The query works fine for the meta keys 'type', 'status' and 'location'. But I'm having problems with the 'min_price' and 'max_price'.

Below you can find the code I used to retrieve a list of users with the above meta keys:

// Values
$type = 'type1';
$status = 'active';
$location = 'London';
$price = 15000;

// Query args
$args = array(
   'role' = 'end-user',
   'orderby' = 'ID',
   'order' = 'ASC',
   'meta_query' = array(
       'relation' = 'AND',
        array(
            'key' = 'type',
            'value' = $type,
            'compare' = '='
        ),
        array(
            'key' = 'status',
            'value' = $status,
            'compare' = '='
        ),
        array(
            'key' = 'location',
            'value' = $location,
            'compare' = 'LIKE'
        ),
        array(
            'key' = 'min_price',
            'value' = $price,
            'compare' = '=',
            'type' = 'NUMERIC'
        ),
        array(
            'key' = 'max_price',
            'value' = $price,
            'compare' = '=',
            'type' = 'NUMERIC'
        ),
   )
);

// Create the WP_User_Query object
$wp_user_query = new WP_User_Query($args);

// Get the results
$users = $wp_user_query-get_results();

// Check if we have users
if (!empty($users)) {
    // Loop through results
    foreach ($users as $user) {
        echo $user-ID;
    }
} else {
    echo 'No Users Found!'; 
}    

This query returns me 'No Users Found!'. However if I use the same values stored for the 'min_price' and 'max_price' meta query, it works. E.g.:

array(
    'key' = 'min_price',
    'value' = 10000,
    'compare' = '=',
    'type' = 'NUMERIC'
),
array(
    'key' = 'max_price',
    'value' = 20000,
    'compare' = '=',
    'type' = 'NUMERIC'
),

Other values than 10000 and 20000 don't work. Any help please.