The Yamaha YTR-2023 trumpet is a discontinued model, so its current value will depend on its age, condition, and where you are trying to sell it.
New, they typically sold for around $700.
On the used market, you can find Yamaha YTR-2023 trumpets for anywhere from $250 to $500. However, it is not uncommon to find them for around $350 if they are in good condition.