Okay, let's go through this step-by-step:
1. The numbers given are: $268, $1258, $654, $1258, $900, $1558, and $852
2. To find the median, first I'll sort the numbers in ascending order:
$268, $654, $852, $900, $1258, $1258, $1558
3. There are 7 numbers, so the median is the middle value. Since there are an odd number of values, the median is the 4th number when sorted.
4. The 4th number in the sorted list is $900.
Therefore, the median value of the given numbers is $900.