Hello Sir,
Greetings for the day! I understand you want a distance based postage charge set up in your wordpress woocommerce website. I follow currently you are manually importing all shops which are within 5 miles of the given postcode by user. I will make the system works as below:
Suppose, user inputs a postcode SW1W 0NY and my query will search the postcodes to which it delivers and make separate lists which are -
1. within 1-3 miles,
2. within 3-4 miles and
3. within 4-5 miles
Next the new 'delivery method' will check the delivery postcode of customer's order. If the delivery postcode is within 1-3 miles of the shop it will add £2 to the total amount. If the delivery postcode is within 3-4 miles of the shop it will add £3 to the total amount. Similarly, if the delivery postcode is within 4-5 miles of the shop it will add £5 to the total amount. I will keep options at back end so you can change the £ amount for each range. This will help you to increase the charge in future when your business will grow gradually. The logic is pretty much clear to me. As I have special expertise in WordPress custom website development, theme development and customization, plugin development and customization, I am confident to deliver exactly the thing you expect. I have developed plugins with critical logic before. I am just highly interested to start right now. Let me know thought regarding this.
Looking forward to hear from you.
Best,
Dipanwita Samanta