First nice looking Dragon.
While I have not built a Bearded Dragon cage I have built quite a few snake cages.
The easiest way to build one is got to home depot or lowes they both sell (laminated particle board) the lamination makes it water resistant (I built a ball python enclosure which has very high humidity and a very large water bowl it is 5 years old with no water damage)it comes in 2 foot by 4 foot sheets,you can make a big cage for less than 100 bucks for the cage and 40-50 bucks for heating and lighting fictures. You do not need to make many cuts. In fact the way my snake enclosure is made no cuts. Stand two 2x4 sheet on end (2 foot side on the floor)oposite each other lay a sheet between each each of the vertical sheet and screw togather at the very top, lay another sheet 2 feet below that one and again screw togather so now you have the top the bottom and the sides togather, stick another panel along the back between the top and bottom now you have a back for the front get two (2) 21 inch long 2"x4" board and two (2) 48 inch 2"X4" boards attach at the corner to form a box 2 inch side facing out. You than buy a 2 foot by 4 foot piece of plexi-glass and screw it on to the outside of the box. add a hing to the bottom and a hock and eye to the top and it is your door. tip lay a 2x4 or 2x6 on edge just inside the door to keep sand, lizards, etc away from the door. drill holes for lights (I added cermic outlets to the inside roof of the cage.