If you don't have sufficient quantities of either Zigbee or Zwave repeating devices, you are going to have a poor installation. It will never quite be "correct" and you will constantly be battling dropped or inoperative devices.
I would avoid these. I am not certain what your outcome may be, but they seem to cause some users trouble. And they aren't all that cheap considering you can get used Zigbee stuff on Ebay and elsewhere for less, especially if you buy in quantities. And as a bonus you can control things like lights or other things. For example, the Iris 3210-l outlets have been as low as about $10 each in groups of 5 ($50 total).
I am probably the last person who should give relationship advice, but I think you and your wife need to sit down and have a frank conversation about budget for this and/or any of your other hobbies. I am sure she also wants to have her own weekly/monthly allowance too, so maybe this is a good time to sit and talk household finances in general. (And no is not a conversation by the way) In my relationship we each get an allowance which includes gas money, lunch/dinner out, and whatever "fun" stuff we want to do or buy individually. If I want something, I either don't dine out all week, or I save some every week until I can purchase something. Theoretically all large purchases above "X" dollars get discussed first.
Anyway, way off topic, but I don't see how you are going to solve this Zigbee issue unless you spend some money by buying devices.