A new suit for podiums etc. is a good idea and an option for some but not all. The best option that I have found is to use Molecule suit care and cleaning products. I have been using it for years on all white or light colored suits that get used nearly every weekend with a junior driver. Suits stay looking like new when washed after every outing.
The Molecule stuff works wonders. They have a Suit Protector chemical that is a bit like Scotchguard. It resists water, dirt, oils, UV rays, grease, and helps guard the suit against staining.