Hello Paddy,
IMHO there is a significant difference between Basic and Pro. However if you have a small bankroll (less than 1000€) I would stay with Basic. If you can hold out then wait until December or next summer, when RB have a discounted membership, and upgrade to Pro.
You will not get many bets on Betfair and they disappear very fast. Also the amount that can be matched is very limited. Remember that it is an exchange. So the bet that is identified can be someone that has a 10€ bet laying and waiting…