A budget build is possible.
As others have said, for saltwater and reef tanks in particular, a standard 55 gallon tank is not the most desirable tank just based on its dimensions. This tank is tall with a very narrow 13" width (the distance front to back when looking into the tank), which makes it very hard to aquascape and doesn't leave the most room for fish to swim. Arguably a better choice would be a 40 breeder, 65 tub, or standard 75 (or 90) gallon tank. These tanks are 18" front to back, which most here seem to prefer for reef tank setups.
Look for used equipment to help save some cash. Look on your local Craigslist or Facebook Marketplace page for used tanks, stands and other gear. You may find someone who is leaving the hobby and selling their entire setup cheap, which often includes not just the tank and stand, but lights, filters, and even nets and algae scrapers. In my experience, these can be a very good deal. Even if they had freshwater fish, this can still be a great deal for the tank and more, and you can resell whatever you don't need, like freshwater lights or decorations.
PetCo is currently running one of their 50% off most Aqueon brand glass tanks:
40 Breeder
75 Standard
Check out the marketplace here on R2R. Lot's of members sell their used or even brand-new, unused gear at great prices. I've found a lot of my equipment here over time:
https://www.reef2reef.com/forums/selling-forum-dry-goods.60/
For a stand, check on Amazon or Walmart.com for some inexpensive options, though you do get what you pay for with something like a stand. But check reviews, and see if you can find something inexpensive to get you going.
I am a big fan of DIY homemade stands. If you have even basic tools and some experience with woodworking, you can make your own stand easily. Lots of different directions to go here from cinderblocks with 2x4's laid across, or a stand built entirely from 2x4's or plywood or even metal if you have the tools and skills. Take a look at the DIY forum here on R2R, do an internet search, or check YouTube for DIY stand ideas. Ask friends, family, neighbors, or coworkers if they have tools and could help you if needed. Most big box stores like Lowes and Home Depot, and many smaller lumber yards, will cut material to size for you, so all you have to do is screw it together at home.
For a tank +/- 55 gallons in size, you'll probably want/need an RODI filter to make freshwater for your tank, so be on the lookout for one of those. You *can* get jugs of distilled water or buy fresh or mixed saltwater from your local fish store, but that's A LOT of hauling water around for a tank that size. An RODI system will save you money in the long run, and be a lot less work hauling buckets of water around.
When thinking about a budget, give some thought to ongoing costs such as salt mix, food for fish and corals, filter media like carbon, supplements, alkalinity buffers, electricity, etc. It seems to never end lol!
I hope that helps! Good luck with your build!
