Could you get away with 14/9? Sure, but you'd probably want a surfboard and a twintip to jump from surfboard + 9m to twintip + 14 m. You really need to think about what your local conditions are like before picking a quiver. I think an 11 would be the kite you'd want under a 14, maybe a 10 but that is pushing it. You can jump from a 14 to a 9, but the truth is a 14/11 quiver would probably give you more good kiting days than 14/9.
Do you typically get winds that are light to moderate? Do you typically get winds that are consistently light plus the occasional storm? How often is the 14 too much, and what are the winds like on those days?
Typically, people will suggest having big kites in 3m increments and smaller kites in 1m increments (ie 14,11,9,7 or maybe 14,11,8,6). A four kite quiver can cover you for damn near anything- 12 to 40+ knots without any uncomfortable gaps. If you get serious about kiting, you'll end up with this eventually, but you don't need it right away.
Most likely, your 14 is often just a little bit too big and rarely way too big- in this case, get an 11 and skip the storms until you can afford a third kite. If, however, you find that the 14 is usually spot on, and the only time it is too big is storm days, that is when an 8 or 9 would be your next kite (relatively few places would have this kind of wind pattern).
I think your next kite should be an 11 unless you find that you often get to the beach and find the wind is too strong to even think about rigging your 14. An 11 would be a comfortable increment under your 14, and more importantly, it would probably be just what your wife would want when you are on your 14.
If you are trying to avoid spending money, here are some tips:
1.) used kites can save a lot of money, but make sure they aren't totally trashed, and don't get anything more than a couple years old. Never buy a kite that needs repairs (new bladders, etc.). Used boards are an even better bet. If there is a local kite group, that would be a good place to look for used gear.
2.) a second board can extend your range far more than a second kite (for example, the kite that I've used that is probably closest to your 14 is a 13.5 best kahoona, with a surfboard it is fun from 10 to about 15, with a twin tip it is just starting at about 13 and I can hold it down to about 20- the surfboard extends my windrange as much as any second kite would and costs way less).
3.) don't feel too much model-loyalty: if you love your current 14, you may not love the same kite in a 9 or 10. Most kite manufacturers now optimize each size, and this is less of a problem than it used to be, but it still persists. Basically, the features you want in a 14 (fast, light-weight, and really easy relaunch) are not necessarily relavent in a smaller kite (small kites can be too fast, weight doesn't matter in a small kite, and all small kites relaunch pretty easily).