calc costs: use default fixed values if prices missing #1107

	name: Python package

	on: [push]

	jobs:
	build:
	runs-on: ubuntu-latest
	strategy:
	matrix:
	python-version: [3.8, '3.10']

	steps:
	- uses: actions/checkout@v2
	- name: Set up Python ${{ matrix.python-version }}
	uses: actions/setup-python@v2
	with:
	python-version: ${{ matrix.python-version }}
	- name: Install pip
	run: \|
	python -m pip install --upgrade pip
	- name: Lint with flake8
	run: \|
	pip install flake8 darglint
	flake8 .
	- name: Test with pytest
	run: \|
	pip install pytest
	python -m pytest tests/
	- name: Build documentation
	run: \|
	pip install -r doc/requirements.txt
	make -C doc html

Provide feedback