Do you like your Sanus, VTI, or Salamander rack?

All of the above, 4" works under sone tables not on others.

I have the Salamander Synergy audio rack with 6 shelves plus 1 pull out shelf for my laptop. Previously I was using a Sanus stand I bought from Music Direct. I noticed an improvement right away when upgrading from the Sanus to the Salamander Synergy rack. It's hard to describe but the system just sounded better all around. I have no experience with the Mapleshade racks or the Walker racks, but an audio buddy in another state told me the Mapleshade rack "sucked the life" out of the music. I have not heard his system so I can not verify this. I would never spend the kind of money the Mapleshade or Walker rack costs. If I had that kind of money to burn, I would upgrade one of my components or invest it in more music.

My ancient solid welded Target is probably better than any of them

and so is Sound Anchor IMO. Hard to find used, but reasonably priced to have made, considering their "last forever" quality. If desired, the Sound Anchor component stands are sturdy enough to put on heavy duty castors so you could roll the whole rack and system out of the closet for cable changes, etc.

I want to move the equipment into the closet

If cost is a big issue, why not simply nail shelf supports to three sides of your closet and use them to support DIY shelves of your choice? There would be many options from simple plywood shelves to plywood/mdf sandwiched shelves or, if you want to go all out, you could concoct a constrained layer shelf using a sandwich of black gatorboard, mdf and aluminum (sort of like the Symposium Svelte Shelves). The shelves could be permanently anchored to the supports, which would be screwed into the wall studs, thereby using the framing of your house, and not the more flexible floor joists, to support your system. I suspect the result would be quite sturdy. By leaving a couple of inches (or more) of space behind each shelf, you could more easily manage cable runs.

My point is, if you can't afford the quality you want, why buy something of questionable stability/quality, when you can construct something better to meet your needs?

Good luck.

Good advice Mitch. I have considered DIY wall mount shelves. Especially since it is only in the closet. One thing that bothers me though is that here in Fl. the floor is concrete with a Terrazo top finish. It is rock solid and I am assuming less prone to vibration than the wall studs which resonate along with the wall board. Just a hunch, I don't have any scientific proof of this but it seems likely. I'm thinking a solid stand spiked to the floor will be quieter than the boomy wall. Anyone out there want to comment on this issue as well? What has less vibration, the floor or the walls?

A slab on concrete will be solid. I was thinking of the suspended wood floors many of us have up here in the north.

My gear is on a Sound Anchor component rack spiked to the concrete floor in the lower level of our house. Consider the Sound Anchor rack. Solid as it gets and holds value. Since you will be in a closet, the castors could come in really handy when trying to change out cables or components. Also, they do not have shelves but instead the gear sits adjustable steel bars providing both flexibility of footer placement as well as better air circulation beneath the components.