I'm guessing at these prices based on memory but here is a representation of how to value your tennis gear.
Late 1970's Corolla $2k, Stan Smith Shoes $12-15, Jack Kramer Racket $20-25. Current price Corolla $20k, Newest Endorsed Shoes $60-130, Newest Endorsed Racket approx. $200. Everything went up 10x since mid 70's as the dollar went down in value.
The quality has improved generally along with the technology so I'd say we're good on most things. Don't buy the latest frame and when you find a frame you love pick up a dozen of them when they are being discontinued. You can always get your money back on Ebay if you switch out.
Pick shoes that work for you and avoid the logos with endorsements that add cost. If you are hard on shoes get and apply shoe-goo at Wal-M and wear those shoes when practicing and not playing or teaching.
Clothing, well that's your call but the modern fabrics are so much better at surviving stains, wear, and maintaining color that if you get the top quality stuff and wash cold you'll have it for years.
No matter what you think the value versus cost of tennis equipment right now is as good as it has ever been. Just don't think that you can buy skill with fancy equipment. Do the deep and repetitive spending on training, instruction , and competition whenever possible.
Addendum: Everything went up but tennis balls. I think they were $2 a can in 1960 and haven't seemed to budge since then. Spend your money on new tennis balls and laugh.
