I have had many free deliveries from Ebuyer. A few months ago, the free delivery was for items at a much lower 'vat inclusive' price of £49.99.
I think that you will find the surcharge is due to your location Aberdeen, which some couriers class as non-mainland.Northern Ireland suffer the same restrictions of very high delivery charges by some UK retailers and UK courier services. Contact Ebuyer for an explanation.
If you paid via Ebuyer/Google checkout, then you would or should have got an extra £10.00 off the final bill.
I should have perhaps mentioned, that the 5 days mentioned for free delivery as never been the case with myself. Goods have always arrived within 3 days, 4 at the most, even from Ebuyer's other direct suppliers warehouses.