There are many reputable vendors that don't charge too much. Most companies will offer discounts, usually on holidays, throughout the year. That's when you can stock up on your favorite juices. I haven't bought enough Halo to know about their sales though. I would advise you to keep ordering what you know you like from Halo, while building up a supply of a few lower cost juices.
You can go to stores near your house and sample juices there for free. You should also look at buying juice in sample sizes (like about 10 ml. bottles) from online vendors. Additionally, find online vendors and sign up for their newsletter so you will be notified whenever they have a sale. I heard about a number of sales that took place today, for leap year, with discounts ranging from 25 - 50 percent off of their retail price.
I've bought juice from a whole lot of vendors, and most of the juice I've bought for less than what you pay for Halo. The vendors I've enjoyed most have been Ahlusion and Seduce Juice. If you google those names, their sites will pop right up. Ahlusion has a 25% sale going on right now and you don't need a coupon code for it. Seduce Juice had a 29% discount coupon they offered up until about 15 minutes ago. Posters have given you other ideas of reputable vendors too so try some new vendors, either in person or online. There is tons of information on e juice vendors right in this forum, so I'm sure you'll have no trouble finding juice you like. If you have questions, or need help, please ask for it here. There are always tons of people here who want to help.