It all depends on what you want to keep. To keep a majority of corals then a 4 bulb t5 or a dual panel led
would be my choice. You can get each led
panel for about $150 on ebay, a little more than your budget but you will have no concerns about not having enough light. I have tried metal halides, t5's and led
's and I lean towards the t5's or the led
I have a single led
panel over my 60g cube now and it is way more than enough light to penetrate the 24 inches deep it is. All the rest of my setups have t5's and I have never had an issue with keeping anything. You just have to budget in the bulbs that you will be replacing every year or so and it comes out cheaper to go with the led
's as they are usually good for 5-7 years easy.
Hope that helps!