Well.... If you look around, you should be able to find a good usable enlarger for free or practically free.
Here's how you can do this. Find one and bring it home and set it up. Then, tell your wife, you'll just need "a few more" things to get started, like trays, tongs, etc. Get that.... then you'll need "just a few more minor things" like chemicals... then paper.... oh, I forgot a timer! How silly of me.... By then, your wife will be rolling her eyes. Sneak in a easel while her eyeballs are pointing up. Soon enough, you'll have a complete darkroom. Right? Right!
After all, your happiness is important to your wife. She'll understand....
p.s. Your mileage may vary. Tax, tag, title extra. Void where prohibited by law (a.ka. the wife)
p.p.s Jokes aside, many things can be obtained for free or nearly free as schools, businesses, and individuals get out of wet photography work. Sometimes, they'll be happy that you'll come and take their "junk" away. I really suggest you look around first and get them used. You'll be amazed what you can get.