I think Lovin has posed a pertinent question. I will expand.
Why does your wife want to spin vinyl?
Legitimate reasons are that you have a legacy LP collection. You want to search for rare material not committed to CD and likely never will be. That you want to try some new thick vinyl pressings. You played vinyl in your youth and are nostalgic for the pleasure of spinning vinyl.
Bad reasons are to think vinyl will give you audio nirvana and be better then digital media. Although properly set up it can be very good, it is not better the digital media.
It my experience unless you have a known source, buying used vinyl is highly problematic. Finding discs that have been lovingly cared for is not common.
Now as a guy who has spun discs for nearly 70 years, I do not agree with most of the advice given above.
Now the first thing to recognize is that playing vinyl is a mechanical act primarily and not electrical. That means there are significant gains as you move up the food chain so to speak. So increase in design craftsmanship of the rotation mechanism, PU arms and cartridges give far greater improvements in quality than in dealing wit digital media.
Your next decision is do you want to go vintage or used?
Next is that unless you have very small speakers I do not recommend a sub. Vinyl was generally cut with a high pass filter at 30 Hz. If not you got very reduced playing times. Back in the day RIAA sections frequently rolled off below 30 Hz to limit acoustic feedback and prevent low frequency problems.
So good vintage electronics is in many ways preferable to a modern AVR if the system is primarily for LP playback. In addition many units had facilities for "cleaning up" rising distortion with frequency. This is a common problem above 7 KHz. The variable turnover and slope controls on Quad preamps being particularly effective.
Here is a very good vinyl rig.
Vintage Thorens TD 125 Mk II with SME series III arm and Shure V15 xmr cartridge, all vintage.
Vintage Quad FM 4 tuner, Quad 34 preamp and Quad 909 power amp.
It is actually easier to add a screen to a good vintage rig, than a good turntable system to a primarily AV system.
Lastly if you have a preamp and power amp, it is easy to add bass management and put in a sub if you want to. Electronic crossovers are easy to obtain, and actually you can do very flexible bass management going that route.
This Quad 44 preamp is the absolute "Rolls Royce" of units for playing back vinyl and will drive any power amp you want. Almost certainly it will have much longer legs than an AVR.
