I want to buy a 128 GB thumb drive.

 

I am looking on Lazada and Amazon.

 

Prices on the former range from 290 – 5,000 baht.

 

I doubt I will use it more than ten times.

 

Will the low end ones work just fine?

The "low end" may be fake (not hold more than a few GB even if they report 120 available).  This is a huge problem for thumb drives of high capacity (even if known brands - the sellers sell and move on).  Perhaps a key indicator will be 'no warranty available' but total scams may not even bother with that out.

If they are not a scam then the low end ones will be only usb 2 speed and will take you longer to transfer the data to them from your pc. They will still be fast enough  to watch movies or anything else you put on them though. I have three or four Sandisk ones that i use all the time without problems.