Unless you have a lot of disposable income, it's quite impossible to provide shelter for all of your animals at retail price. On the flip-side, there are some bargains at the pet store that are beyond belief. You can buy a ten gallon glass aquarium in most places for about $6.95! It's too bad they are too big and heavy to deal with for most tarantula setups. Don't shop any further, or prepare to suffer and be confused. Just when you begin to trust them for practically giving you this item you discover that a five gallon aquarium costs about $10.95, while a two gallon is priced at (you guessed it) $10.95.

Now wait one minute. No one said I had to do math today. What's going on here? Reverse exponential osmosis? Call Judge Judy. Sam Kinneson, please come back to life for a moment and yell at these people. Whatever is wrong?
I decided to let someone else deal with it. I could not gather enough courage to ask the pet store employee why prices double as aquariums get smaller, and oh, did I mention that the aquarium lids cost twice as much as the tanks? You have to buy a lid when you keep spiders, but the screen and flip top plastic lids don't work too well for large spiders. I think I'm gonna cry now.
Time to cheer up. You have choices. How about those plastic pet homes with the ventilated, snap on lids? Pretty neat. Great handles on those lids. Don't use the handles! Throw them away, or if you just can't bear to trash them, stash the handles in your junk drawer. I have a fine collection of plastic lid handles. I have all the colors except for hot pink. I was thinking of mailing them back to the manufacturer.
The smallest plastic pet cage is only $3.95 and they work great, but the larger sizes are near the $20.00 range. At least with plastic cages the pricing scheme follows the laws of the jungle, meaning the bigger ones cost more. People, you must remember that this is an EMPTY PLASTIC CONTAINER, and there is no empty plastic container on Earth that is worth more than a couple of bucks. Don't part with your hard earned cash so easily.

The vocabulary word for today is "cheapnis." If you spend more than $5 to complete this project, something is wrong. Please follow these few simple steps to make your very own custom-designed tarantularium. Your self esteem will sky-rocket. Be cheap, and be proud. Use the money you saved to buy more tarantulas! Use your imagination and improve upon this basic idea, but remember that simple is beautiful.
How to build your own (arboreal configuration, as shown) Tarantularium:
1) Purchase a clear, plastic storage jar with a screw on lid. One gallon or larger works well for this project. They cost about $3.50 at the supermarket. If you are skeptical about buying an empty container at this price, go to your local wholesale food warehouse and buy the jumbo plastic container of generic brand pretzels. Eat the pretzels. Congratulations!
You've just acquired a plastic storage container  free of charge! Now, do you feel better? Are you thirsty?
2) Make ventilation holes in the lid, and a few near the base of the container. Plastic is easy to work with. Perforate it with a small drill, or use a low wattage soldering iron. Holes located at the top and bottom allow for cross ventilation, which may be essential for the tarantula. If you melt holes into the plastic, don't burn it and don't inhale the fumes. Do it outdoors.
3) Find a cylindrical piece of scrap foam pipe insulation. If there's none in your garage, ask your friends, somebody, somewhere has this material laying around. Cut the foam to a suitable length. A six inch section fits well into a one gallon container. This will be your spider's hiding place. You may cut holes in the side of the foam cylinder as shown. It creates nooks and crannies for the animal to lurk, spin, and crawl around within.
4) Cut a notch in the side of the foam, large enough to insert a bottle cap or small jar lid, which will hold drinking water and provide some humidity for the enclosure. I placed my water dish near the top half of the foam.
5) Attach a plastic aquarium plant to the foam for that "natural" look. Hot glue, or a stapler works just fine. The plant gives the spider more hiding places. My arboreal spiders drink water droplets from the leaves. Use plastic plants that are easy to clean.
6) Attach the assembled foam, water dish and plant vertically to the inside surface of the container. Hot glue will do the trick, or try Velcro strips.
7) Choose a substrate (sphagnum moss, peat, vermiculite, soil), and put about a one inch moist layer at the bottom.
8) Add water to the dish; add one arboreal tarantula and enjoy.*

*If you prefer terrestrial tarantulas, go "horizontal" with this container. Just make sure it won't rock and roll. Glue some feet to the outside surface and lay the whole assembly on it's side. Relocate and reposition the water dish.
By the way, I didn't mean to make fun of pet stores. It is very hard for anyone to run a business like that, and anyone who succeeds at it deserves a pat on the back! I just think that they generally have little amusing quirks in their retail strategies that needed to be pointed out. No major problem for "we, the well informed." I really enjoy spending time at many of the local pet stores. I support them and place much value on what they add to my community. Over the years I've made friends at all of them.
One summer day, I put my huge Theraphosa blondi in one of those tiny plastic Pet Pal cages and brought her to one of the shops. I complained to the owner that the cage he sold me was way too small for my spider. He never saw a T. blondi before. He never forgot that day.
Best regards to all until next time, and remember I'll be here safely hidden behind my hunting blind. Be wary as you pass by.