I been making my own Hamburgers for years.
I just buy minced pork from Tesco,chop up an onion,add an egg ( eggs depending on the amount of minced pork ) some Pork powder and a dash of Oyster Sauce.
Once mixed I spoon Minced Pork into small Plastic Bags ( 3 1/2" x 7 " , the hard polyethene type bags )

Once the bags are half full I fold them over and tap them flat into square patties
If cooked from frozen they never fall apart but quite often I get one out from the fridge the night before .I cook the minced Pork and once cooked I add it to some beaten eggs and make a nice Pork Omelette.( A nice low carb breakfast or light lunch with a little salad )

So for about 100 Baht you can make 10-12 Burger and have portions of minced pork at the ready that can be used for all sorts of Thai and English recipes once defrosted