Yes, R600 per night for a bachelor flat in Pretoria CBD is reasonable, especially if it includes amenities like security and is well-maintained. The rate is in the budget-to-mid-range category, as daily rates in the area for secure, private flats generally range from around R500 to R800. Prices may vary depending on the exact location, security features, and furnishings, but R600 should get you a decent, comfortable space for a night in Pretoria CBD.