You're still getting lots of great advice but:
You're the person that's going to connect and be with this horse 24/7. Just make sure whomever you choose has a healthy conformation that won't cause it problems later in life.
My three Walkers are built different, have distinct personalities and travel different. Truthfully I doubt any of them would have been a choice for anyone that seriously critiques horses and are looking for absolute perfection.
The fella in my avatar was 16 when that was taken. He will be 25 next month and has been my heart horse for 22 years.
He was my first TWH and I was gait-stupid when I bought him ---- thank goodness because he's been a fantastic-no-fear-go-anywhere-back-down-the-male-llama-show-off-in-a-parade horse that I could ever ask for. I bath him without a halter and he walks beside me when I say "you're done, let's get in your stall". That has to be worth a dollar or two.
And he performs that dreaded stepping pace. He performs it every bit as smooth as my Generator fella that does a champagne-smooth running walk but, nonetheless, 99.9% of the population turn their nose up at his stepping pace and they refuse see his other qualities.
So to repeat myself, as long as the horse you choose does not have any physical issues, the gait is comfortable for you, and you feel like you trust and can build a relationship, then that's the horse for you.
That's not the "two cents" I would give to a novice 65 yr old rider but, you've got plenty of experience, so good luck.
As far as the $3,500 --- yeah that's an awful lot of moo-lah in this day and age of free and good horses with papers BUT, if you can swing it and this is the horse you want, you have earned the right in this life to spend too much money.
My life long friend and trail riding bud is a cancer survivor. She spent $5,500 on her KMSHA and another $3000+ on her custom-made Steele saddle for that horse.
She saved up her money until she had enough to go shopping for the horse and saddle she WANTED.
She's had the horse around four years (I've lost track
and the saddle a year less. They go sloggin' thru the mud up in the mountains, have found themselves in the middle of motorcycle poker runs on the same mountain road.
The horse performs beautifully all the time for her. He's not what I would've picked. But who the Samhill am I to tell that woman, who has worked all her life and survived cancer, she's spending too much money on a horse that had issues early on and a saddle that she will never get her money back out of?
I didn't mean to write a book - but you get the point - do what's right for you and if you have that money ---- spend it on what makes you happy and brings you comfort
Being crappy 65 years old has to have some perks for us - I sure don't know how I got here this fast---------------