A few seconds;

- I REALLY second the safety angle of owning your own ship. Safety is always a PRIMARY concern for my wife.
- I second that a club; won't let you, or limit you, on XC flights - be angry if you break something - won't like you being a "zoomer" (come/go/not-help) - might have expensive fees - forces you flying only a few locales instead of anywhere - might have the "wrong", substandard or missing safety avionics (i.e. xponder, FLARM).
- I second that your glider partner might not want you to take "his" ship for weeks at a time. So you need to figure to go it alone.

One idea is to try the club-only-ship approach for a year. After a year of your wife hearing your repeated complains, she might see the light. Also, keep a spreadsheet of "club" expenses to prove your financial points.

Good luck, John