It will depend on your playing level and regularity of training and games. However the average goalkeeper should expect to use 3-5 pairs a season due to the nature of goalkeeper palms/latex wearing down.
This is normal so please do not worry when you begin to see your palm wear - it can happen from the very first use on any glove, but all our gloves come with 4mm of latex and will perform until there is physically nothing left.
You can help offset that by relegating your worn down pair to training while saving your fresher pair for game days. And then continue to rotate throughout the season.