$400+/GPUs. Is it worth it?

Recent hype of litecoin mining lead GPU manufactures to hike up the price by $100 in a matter of week. I purchased my Gigabyte R9 280X just after Thanksgivings for $320s each. Now, many retailers are selling for $420s and above. Along with current flow of market, even used ones started to appear everywhere and being sold close to the brand new GPUs. Is it worth buying for mining purpose?
Let’see. For the price of $320, R9 280X going about ~700 KH/s, it’s calculated to be ~$2.19/KH. I found out that 7950 used to be mid $200s before the hype, which would have been even cheaper $/KH. With current difficulty, it won’t be easy for any miners to even out the cost invested on GPUs, especially with $400+/GPU. I am currently running little above 2MH/s with 3 GPUs and it has been about 4 days. I am almost at my 3rd LTC averaging 0.6~0.7 LTC/day. I have been considering to have 2nd rid to aim for 1 LTC/day. That brings conclusion that I need to have another rig just as what I have considering immediate increase of difficulty in next a few weeks. I spent about $1300 for the rig that I am running and I calculated that it will take about month and half for me to even out the cost that I invested and that is not even considering the increase of difficulty. So, if I decided to make another rig with current price of GPUs, it will add up another $300+ in total. hum… this is starting to give me second thoughts. I feel that as I try to get a step closer to the goal, the goal just steps away with my pace or faster. hum… One time, I saw Newegg listing brand new R9 280X for $419. Surprisingly and interestingly, those weren’t sold out for couple of days. Usually, GPUs sold out in matter of minutes. I think more people are start to think that it’s not worth that much to buy GPU. On top of that, people who bought earlier and spent $100 less are beginning to list on eBay for short profit. Those usually are sold for mid to high $300s. I saw some being sold for more than $400, I wish luck to the buyers. Thus, until those pre-purchased GPUs are out of market, $400+ GPUs won’t go out in stock as quick as it used to be.
So, my final conclusion is to over invest on not just 2nd rig but also 3rd and 4th rig right away, that is IF I can purchase GPUs, and over run the difficulty for a bit of time or just get out of ego and enjoy the ride of new experience in cryptocurrency. The worst scenario is that I have 3 killer GPUs and I can sell for $100 more than what I bought and a few LTCs that I collected so far. Um… it doesn’t sound not that bad at all. But I am still not sure about $400+ GPUs… maybe better luck on eBay or consider other GPUs that produce less KH/s but better bang on the bucks!