Cultured marble is easily repairable. The problem is, it is now mainly mass produced rather than by local independent tile contractors (my father made cultured marble vanities, lavatories and shower surrounds for more than 30 years; it was a logical extension of his tile setting business and had four long countertop molds set up in his shop). Unless it is made locally, no one is going to repair it. And if it is not repaired promptly then it will need to be gutted. To me, cultured marble was a good product in its heyday but is now a dated look.
For low maintenance, Corian is a good choice. Re-bath has both acrylic and stone veneer surrounds that have a honeycomb back for added strength — these are not like the sometimes flimsy surrounds often found at big box stores. An option that would fit under a $5,000 budget is a MAAX Utile system (available in a Carerra look); available from Lowe’s or Home Depot. The three walls, base and sliding door cost about $2,000 for a 60 x 32 shower plus installation. It looks like subway tile but is one piece per wall.
Here is a pic of the MAAX Utile.
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Corian
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