I very rarely blow the whole budget on one player, but I almost always spend ALL of my money, maxing out transfer funds against wage budget, on four or five players, then come almost to bankruptcy before relying on end of season prize money to dig me out.
I usually keep my keepers until a very old age, sometimes right up to 40, provided they are still putting in the performances. But also my second and third choice keepers are also world class younger keepers, who I have as successors but also to keep them out of the hands of other clubs. It is a constant battle to keep them satisfied with cup matches.
Actually, I am a bastard for this, signing expensive players I really, really dont need just to stop other clubs getting them. I frequently have more top class players than can fit in my 25 slots.
Yeah I'll retain keepers until their early 30s, but I'm ALWAYS looking to upgrade and cash in on him before his price drops. Generally though, I won't sell until I have a replacement lined up who is or will shortly become much better.
Ha! I like really like it when my boys beat club records though (most goals, most appearances, even oldest player!) so I often keep giving guys who have been there a long time more games than they deserve to get them over the line. In 2012 I once played Niang consistently from the age of 16 up to 35.