Hi Leah, the simplest way to get into Modern Pentathlon without massive outlay is to look at competing in the 5 elements separately, so finding Laser Run competitions that he can enter ( as Kevin said, in Europe most events offer rental equipment for this exact reason and i would guess the US guys would to ) swimming is different as it is a 100m sprint so you can cover this in his normal training, OCR is what it is and you can get a great appreciating of the MP version by looking on Instagram like ours at Pentashot UK and other UIPM channels. Doing Biathlons, Biathles, Triathlons and Triathles will also prepare him for the hectic transitions which make MP such an exciting sport to do. The mistake a lot of people make is trying to start with MP when actually it is best to do the others first. I hope that makes sense and is a help./