You can ask for the Care and Maintenance Instructions to see what it takes to keep it 'nice'. Also, get a copy of the Warranty too. You'll find interesting information in BOTH documents.
Vinyl, being soft, will show wear quicker than almost anything else. I suggest you buy a color that won't show slight damage and won't discolor over time. Sure, there are chemicals that will 'damage/dull' the vinyl so, again, get the aforementioned paperwork. You probably can't even use a 'soft' scrubby brush or Soft Scrub.
You know - You get what you pay for. Shop the OTHER Tub Materials and find out why one costs more (or less) than the other. And ask each Retailer why you should spend more (or less) than something else. That, too, is an education!