1 x Tabletop (100cm x 60cm) :: VIKA AMON from IKEA :: $5.99
2 x Adjustable leg :: VIKA KAJ (OLAV) from IKEA :: $30.00 ($15 each)
2 x Hanging Track :: Habo from STARK (Dansih hardware store), but HomeDepot has something similar here) :: $13.1 ($6.55 each)
2 x Twin Track Brackets (reinforced) :: Habo from STARK, but I guess you can find it in HomeDepot also :: ~$11 ($5.5 each)
NB: The IKEA VIKA KAJ legs have a maximum height of 90cm (~35.5 inched), so I needed to make two blocks of wood, that can can support the weight of the table when it is in "standing mode". This can be avoided if you can make or find some legs that can be extend to your liking - e.g. IKEA has the VIKA BYSKE that can be adjusted from 70cm to 107cm but that was not heigh enough for me. I am sure this part of the project can be done in a smarter and more beautiful way (see step 4).
Hex shank spade bit
Total cost: $60 + wood and screws