It can range from 2.5K -> 50K... Depending on the brand.

On a budget, go for Heng Long. 2.5K-6K (depending on your bargaining skills). Available in 168 in the divisoria area.Though they may be cheap, mind you, they are excellent platforms to deck out with details.

If your budget permits, you can also check out Tamiya. around 29K -> 50K. Available thru Lils. If I'm not mistaken, I saw a Tiger 1 and Leopard 2A6 in stock at Lils Makati.

Here are a few sites you might be interested in visiting:

http://www.rcuniverse.com/forum/forumid_369/tt.htm

http://www.rctankwarfare.co.uk/forums/index.php

For online stores:

www.etoarmour.com

www.rctankwars.com

Hope this helps.