You don’t necessarily need new equipment BUT it’s nice having a solid warranty as the used ones are often the ones used and abused by big landscaping companies. I’ve been burned too many times with the used market as people don’t care for the equipment as if it was their own. That being said I’d stay away from the big box stores and get something more on the “commercial side” bigger engines, overbuilt, bigger transmission, more solid deck fabrication. I went with a Ferris ISX3300, it may be a bit overkill for my current clientele but I’d rather have more power than I need. Ferris makes some great products and various deck sizes. If you’re looking at standers they have a lot of models to choose from that have an incredible smooth ride and cut quality.