Avent pump is not suitable for all 肥奶樽. For example, it cannot be fit onto B-free bottles. You can try asking the sales first.
Before my B was born, I was like you, because I was not sure if I can breast feed, so at that time, I did not want to spend too much $ so I only bought a small Medela Mini Electric pump, just to try. But later, when I was able to breast feed, and have to go to work, the Mini Electric is not so useful because it takes a long time to pump and it is noisy. I now have 4 pumps:
1 Mini Electric I don't use anymore, 1 Medela Pump in Style (from my friend) I use in the office, 1 more Medela Pump in Style Advanced I use at home which I bought 2nd hand from a BK Mami, and 1 Avent hand pump!
Actually for the 1st month after giving birth, if you are feeding directly from your breasts, you really don't need to use your pump. So I think you can wait and see. But I suggest that you select the pump that you want to buy, and where to buy, so that just in case during the first month you can't leave the house but need to use a pump, you can still ask your husband or other relatives/friends to buy it for you.