The medal index rolls only list one Gerald Price without a middle name. He was in the machine gun corps service number 96314. The service records (and keep in mind that some 60% of WWI service records were destroyed in WWII bombing) for this chap did survive and as Suzanne said do show a middle name of Henry - though only on two of the pages. On all others he is merely Gerald Price. The service records indicate that his parents were in India during the time he served. If the family of your relative were never in India this man is not him.
The medal index rolls (which are complete) list three others though all have middle names: Gerald A Price, Gerald Percy Lawrence Price and Gerald W T Price. If he is not one of these men it would appear he did not serve or if he did serve did not go overseas which was one of the requirements to receive a medal.