piztaker:
That doesn't bother WGT - you will be asked to buy more credits in the buying sequence :)
sheak, there are no buy buttons in the category view. You'll have to select one item into single view, then there should be a "buy now" button, even if the item should be locked for any reason (e.g. level oder tier).
Possible problems:
- you changed the zoom of the windows. Then the button might disappear behind the Players Reviews. Resolve with <ctrl> <mouse wheel> (this is how I did it).
- there may be an issue with Flash - clear the cache.
(list not exhaustive)