Definitely a bottle steriliser is more convenient.
If you do intend to get one, you have to descale it every 3 weeks or 4 weeks.
Mine is the Philips Avent steriliser. Rather durable. Have been using it for a year already. Find that this steriliser I can stack a lot of things. Also coz I'm using Avent bottles so would get back an Avent steriliser so that I can maximise the space usage of it for the bottles.
If you want something affordable maybe you can consider a second hand.