Stock GTS aluminum alloy wheel weight is about 19lbs each/without tires. The 30lbs you mentioned, is probably the weight of your new wheels with tires. Each. And as a "Shipping Weight," which includes the box and any other packaging/cardboard/tie-wrap materials.
Some online wheel shops mark all 15" wheels/tires as one weight, and all 16" wheels/tires as a slightly higher weight, and all 17" wheels/tires as another slighter higher rate. Rather than weighing everything individually. Also, some shops just mark all purchases
online as one weight. And even further, some shops ship out all "wheels" as one rate, and let their shipping company deal with the exact weights. This is also true for companies in other industries, such as DELL and HP, when they ship a "custom" desktop PC out to the end-user.
If you are feeling uncomfortable about your purchase, call up the shop and ask all your questions about the wheels to the shop manager. If the shop you purchased from doesnt know much about the wheels, call around to other shops that sell them. Ask as if you are "just shopping around and you had some questions before buying," even though you've already purchased a set.
Here is a site where you can get an idea of how they will look on your Celica:
http://www.autoanything.com/wheels-rims/vision-463-xcite-wheelsTheir image overlay is a bit goofy, but the wheels do look good on the Celica. Nice buy!