I recommend you try mining with your current hardware first for Litecoin and a less popular altcoin like Yacoin, then look to invest in hardware. Litecoin is popular enough that it will take you multiple weeks before you earn enough in a Litecoin pool to withdraw.
You can compare Litecoin hardware output here:
Yacoin is up and coming but is still low in difficulty enough that you can earn enough in a day or two and while using your CPU.
For an example to put it in perspective, on one of my machines, I mine for Litecoin using my GPU and I also mine for Yacoin using my CPU. I am getting close to 5 Litecoins mined but I have already mined over 700 Yacoins.