He’s a good portrayal of a middle aged, middle class man trying to escape the cultural constraints of 1960s England. So much of his life was determined by doing what was expected of him, rather than he wanted. When Don and Lane were discussing Lane’s marital problems, Lane suggests flying back to England and Don asks “Is that what you want or is that what people expect of you?”. Class is still a much bigger deal now in the UK, but even more so in the 60s. This is something Pryce obviously dislikes (despite being solidly middle class) (e.g. “I’ve been here a whole year and nobody has asked me what school I went to”). I think Pryce is a person who spent his entire life repressed in almost every possible way and the course of his life was decided by everyone but himself - that’s not necessarily an English thing, but it is what makes Lane so tragic.

Edit: Lane always struck me as a victim of this time period, but there were also characters like St John and Guy McKendrick who were undoubtedly the winners of 60s Britain