The development cost depends on the range of required services. It can be a template or a unique design development according to the WordPress coding standards.
Approximate development costs by process:
1) Basic WordPress and WooCommerce setup with template installation: about £400 (depends on the specific template).
2) Functional development: from £150 / medium complexity plugin development.
3) WordPress template development based on a mockup / layout: about £900.
4) Website design development from scratch: from £1800.
In total, the total website development comes from £400 to £2200.
Also, the website development can be extended by related services: content filling, texts translations, SEO research, interactive and other visual effects.