1. I don't see how this is eBookers' fault (and I'm no fan - when I had a flight booked with them that the airline changed to a crazy layover, they were unable to fix it even though the airline had availability).

2. Emirates' restrictive fares are not news: sometimes there can be a very small difference in price for much less restrictive fare rules.

You could probably

At the end of the day, low fares like this are not a scam: but travellers do need to be aware that these fare buckets are so cheap, partially because they know that the prohibitive change fees mean that they can actually sell more than they will be required to deliver. You're getting the benefit of that because the fare is so low.

For what it's worth, I think the Emirates ticket actually offers no refunds or changes on the fare: they may be selling you a replacement one-way for £386. The fare rules certainly suggest no changes except due to death of a family member, which I assume is not the case for you.

Having looked via ITA Matrix the cheapest one-way BKK - LHR in June is THB 12875 (which is just over £250).