I usually send the package that has values less than 10 GBP by standard shipping with no tracking number.
Thai post office can check if the package has arrived in your country and give an estimated time frame when the package would be delivery to the recipient.
I would be more than happy to refund your money regardless you receive the package or not.
Alternatively, I can send a new package by a registered mail ( it'll have a tracking number for you this time ) without additional charge after you get back from your trip.
Please let me know your preference.