Twig merge 2 arrays based on value/id - arrays

Question

I'm creating 2 arrays with objects in a Twig template. I know it's best to handle this not in the templates but there is no other way to do it (SaaS platform).
I have 2 loops:
{% set opt_arr = {} %}
{% set var_arr = {} %}
{% for opt in options %}
{% set opt_arr = opt_arr | merge([{'title': opt.title, 'id':opt.id}]) %}
{% endfor %}
{% for var in vars%}
{% set var _arr = var _arr | merge([{'title': var.title, 'price':var.price}]) %}
{% endfor %}
/* result equals something like this =>
[
{"title":"used","id":123},
{"title":"good","id":213},
{"title":"new","id":321}
]
[
{"title":"used","price":199},
{"title":"good","price":299},
{"title":"new","price":399}
]
I want to join them to a single array like so:
{"title":"used","id":123,"price":199},
{"title":"good","id":123,"price":299},
{"title":"new","id":123,"price":399}
I tried several things but either it won't join on title or it removes some data.
{% set all_data = [] %}
{% set all_data = all_data | merge(opt_arr) | merge(var_arr) %}
Or
{% set opt_arr = opt_arr | merge(var_arr ) %}
What am I doing wrong?