I don't know the cost of water at VIP, but I think it must be fair because I've seen people lined up for it on the weekends. You won't regret checking them out. As soon as you walk in the door there is a beautiful display tank full of really nice rock flower
anemones, or RFA's. VIP is known for selling high quality RFA's and that tank is something to see. That's not all though.... they have HUGE reef displays and nice frag tanks too.
Also though, the cost of a DI stage would eventually be less than the continual cost of buying water, particularly when you factor in your time and gas on multiple trips. You might want to look at the DI stage sooner rather than later. Of course, mixing your own saltwater means you need a spare pump to do the mixing and a spare
heater to match temp.
So, the saltwater they sell at VIP is ocean water and they can send it through pipes in the wall to deliver the water straight to the outside. So, you can fill your container without even having to take it out of your vehicle. Speaking of water containers, I'd suggest looking at Brutes, (food safe, and they do come smaller than you'd think, I have a 10 gallon capacity Brute.) You would do well to keep spare saltwater around while you are unable to make it at home. You never know when you might have need to do an unexpected or emergency
water change. You'll also need to keep RODI water around for freshwater top offs. Condensation can be an issue with nano tanks because
salinity can change rapidly in a smaller volume of water. Your hood will help with that though you still might think about an ATO, (auto top off) unit. I run a 20 gallon long with a glass lid and I need less than a gallon of RODI per week for top offs. I don't have an ATO.... yet. I'd like one.
I've purchased coral and dry goods (both at competitive prices) from VIP, but not fish. They don't have a whole lot of
nano fish there actually, mostly clowns and larger fish. One thing though, I did first introduce
aiptasia, (a pest anemone), to my tank through their
chaetomorpha, (a macroalgae for
refugiums). I don't hate them for it though, most of us will encounter aiptasia eventually. Also, the chaeto tank appears to share water with another tank that they sell cycled wet (maybe live) rock out of. It does not appear to share water with the frag tanks, (though you should always dip corals anyway), and the RODI and Saltwater they have for sale is completely separate from livestock.
You know, you and I are lucky that we have a lot of salty LFS's down here. Yay!!! No
shipping charges. Well.... someday I hope you can take advantage of the online live sales that World Wide Coral (WWC) has. They are in Orlando, but shipping from them is $10 cheaper than it is for those outside of FL. WWC is well known for having bright, beautiful and healthy corals.
There's also Reef Top on Saltwater 87 Avenue. Their tanks are a little messy, but I bought my
firefish and my one of my favorite corals (a duncan) there. I particularly like the look of Ocean View on Bird for fish, I haven't bought there yet but hope to get a
goby there very soon. And if you check out Ocean View, you may as well see Simply Fish, they're right up the road from each other. I'm even further south than you in Homestead, but I've made a few days of visiting the local reef stores. The ones I've mentioned here are the best I've found. Sorry for the long post and getting ahead of myself. I'm excited to finally share these LFS's with someone who can actually go to them.