That's an average of about 180,000 GBP worth of weed per suitcase.
According to Mr Google the average street value of cannabis in the UK is approximately 10 GBP per gram. In Thailand it's about the same.
So I don't understand why anyone would invest 180,000 GBP for very little profit, and take the risk of jail time (and losing all their investment).
Perhaps someone with more knowledge will enlighten me.
Smuggling cigarettes would be much more profitable (Thailand 40 THB per pack, UK 14 GBP - 600 THB). I stopped smoking 20 years ago so I'm just getting those numbers from Mr Google.