I have found an unregistered one word domain with the .HT ccTLD. When I type the word in Google, 1,800,000,000 (1.8 BILLION) results show up. The domain has been previously registered, and the less-valuable form of the word is registered. Needless to say, all gTLDs are taken. Should I go for it? I'm not very rich right now, so I need to make sure I'm spending my money wisely (It would cost $134 to purchase).
you need to have a plan of what to do with it if you have a business plan and the purchase supports it - then yes - if not - no
If possible try to check the history of the domain. I'm sure I've heard of folk buying domains that were previously banned that have caused them subsequent problems