So… I am not the specialist so posisby someone else can write this better but…if the json is stable then you could go for the no. of the record, else something like this with checking the length first
value_template: >
{% set y = value_json.Price | count %}
{% for x in range(0,y) %}
{% if x = y ....
if you need more help than this I may have time tomorrow (or maybe someone else with good ideas)