Dragons need a UVB producing bulb and a heat producing bulb. As babies they can be kept in Sterlite tubs roughly the same size as a typical 20-30 gallon long tank. For the heat lamp you will need to buy a clamp light fixture (can get these pretty cheap at hardware stores, check the rating on them so you know the maximum wattage of bulb they take...most I have seen take up to 75 watts, which should be okay for this setup). Make sure you clamp it so the sides of the hood don't touch the sides of the container, you don't want to melt it.
For the UVB bulb, tubes are best and cheaper than Mercury Vapour bulbs. What I used for this sort of setup is an 18" under cabinet florescent fixture. I mount this to a length of wood which I just lay ontop of the container. I removed the bulb that comes with the fixture and the plastic covering and replaced with an 18" UVB tube (such as Repti-glo 8.0's)
Substrate I just used paper towel. Basking spot can be anything that is sturdy and allows the dragon to get a bit of height (keep in mind you don't want the dragon closer than 6" of the bulbs, else there is a risk he could get in contact with the hot bulb and burn himself).
This setup is pretty cheap but only good for about 3-6 months, depending on growth weight. Once your dragon is about 14" he is ready to be moved to his adult home, which needs to be AT LEAST 4'x2' of floor space. Height can range between 18-24". The cheapest way to get the adult cage is to build it yourself.
Keeping an eye on sales, garage sales, checking at aquarium supply stores (sometimes they get tanks that leak and sell them for cheap...) is the best way to find a decent large aquarium type tank.
Heat bulbs you can buy at any department store, flood style outdoor lightbulbs is what I tend to use...they last longer and tend to produce a good amount of heat and light. UVB bulbs are going to be the more expensive, only known these to be available at pet stores, reptile shows and online order. Shop around to find which source is cheapest for you, keeping in mind if you order it online, you do have to consider in shipping costs.
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PHLdyPayne