Which budget lens is the best buy for a brand new Canon R50 if I only have about 300-400 dollars left to spend? Im leaving for a trip to Chicago in literally four days and I need to pull the trigger tonight.

I am torn between getting the RF 50mm f1.8 prime or just trying to find a deal on the RF-S 18-150mm zoom. The 50mm is super cheap and fast but I worry itll be too tight for walking around the city, while the 18-150 covers everything but its way more expensive and might push my budget too far. Is the prime worth the hassle of not being able to zoom in and out?