How do the AIS (or other ?) trade in your old phone offers actually work?

[notrub]

I would like to buy a Galaxy A54 5G which comes in at ~12-13,000 baht.  I have a bunch of old samsung phones.  I plan to switch my 3BB account to the 500mbps and get a second sim card with that package (thanks GammaG). 

 

How does it work to trade in a phone with AIS or any service provider please?  Is there a cheaper way to get a hold of an A54 5G other than Lazada or Shopee?

 

Thanks in advance for any comments 🙏🏼

[Ralf001]

https://ais-tradein.remobie.com/

[mfinasi]

If you're paying cash there and then I find the independent small vendors good as, you don't have to go MBK, even top floor Asoke Terminal21  has a few, I was able to negotiate around 800baht off a 7000baht base model. 

[KannikaP]

5 hours ago, notrub said:

I plan to switch my 3BB account to the 500mbps and get a second sim card with that package (thanks GammaG). 

Switch to 500mb/s from what. I read that 3BB is either 500 or 1000.

And the SIM card is included with no further charge?