Old answer in that we once had a shower made of resin panels, popular in the 80s for sink vanity combinations, and I loved it as it was so easy to clean...done i a subtle cream.

The Spruce: Best Material for Shower Walls

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• Swanstone Shower Walls
• Wilsonart WetWall
• Avonite Solid Surface Shower Wall Systems
• Transolid composite acrylic polymer and natural stone
• Maxx Acrylic
• American Standard Shower Walls

We have three bathrooms- two with showers only and one with shower/tub combination and replaced tile in all with Swanstone solid surface. Love it- easy to clean and looks great. We used a matte white. Well worth the cost. All of the Swanstone was ordered through Home Depot.

Can recommend Whink Rust Stain Remover- only reason my shower walls, tub, sinks, and toilets aren't permanently orange stained despite having whole house water conditioning system. Instant rust removal! I order from Amazon in quart bottles since local stores have stopped stocking it.

I love my Maax tub/ shower combos I use for clients andalso the showers. Why make life complicated easy to install , easy to clean and no way to leak. I have a tub/shower one in my home for 16 yrs still looks exactly like the day we put it in .

None of the solid surface options are mid priced. Even cultured marble will run you 6-9K. Corian is double that. The cheap acrylic are the best budget choice. A properly built tile shower, by an actual tile pro, who knows how to waterproof, is going to run about the same, or more, depending on materials choices.

You could also consider doing a larger format tile ( 48W x 24h or 30 x 30 ) . Yes you would still have a grout line but if you get a better quality grout, you shouldn't have problems with the iron in the water. The tile is simple to clean off with a squeegee.

Some of the solid surface walls - Corian, Swanstone, Wilson art are awesome but can be pricey.

Also, if you have a lot of iron in your water, you may want to look into filters for that.

If budget is part of the issue super large tiles are not the answer the install alone requires a tile setter with better than normal tile setting experience.

We did white cultured marble. I know it’s not a poplular choice, but I hate, hate, hate cleaning grout. So far, they’ve been great - easy to clean and decent looking.

I think my Dad got sheets of 1/4” thick corian and fabricated it himself. He made me a cutting board from the leftovers. I remember the seams in the shower were covered by another 3” wide trim piece of corian with polished eased edges.

I was told to get white scotch brite pad scrubbers to buff scratches out of a corian countertop. I assume that could be used to polish edges but my Dad may have used another surface and tool.

If the floor was the problem, you could get a shower base if you don’t want a tub or tile. Kohler used to make a cast iron shower base. When I had a walk-in shower, the floor was always the source of the leaks. I have used tubs ever since.