While I agree with all the caution people have sited, compromise is part of any purchase. So, the question for me is - why do you want to purchase him?
When I was breeding my horse, my trainer asked me if I would be happy with a clone of my mare. While you always hope for an improvement on the next generation, anything is possible. So, would I be happy with a nutty, athletically somewhat limited horse (she could jump 3’6" but topped out at Training because Prelim height was a max for her so could be an issue on XC, she also was correct in dressage but not fancy). I am extraordinarily pleased with the product - much more sane, much more athletic, loved by all - BUT I would have been happy with the clone.
So, the question is, what other aspects attract you to him? Is his personality enough that if his soundness limits him you would still be happy to see him? How fixed are you with your goals, are you willing to adjust if he is not adjustable? This could be anything from soundness to personality (you say he hasn’t been off the farm in a while, he may have a meltdown when travelling).
I will give you a few examples of pro/con (these are all horses I currently ride, gender is not a factor for me so I am leaving that out).
Horse 1 - needs a dominate personality and I don’t have one so it is a challenge and a bit exhausting for me to ride, though horse has gotten much better now than when we first started about a month ago and overall better than when I was riding it last fall (that was a disaster!) Horse also tends towards being stiff so is hard to get going well and a bit on the lazy side. Were I looking to purchase, I would walk away
Horse 2 - cute, friendly aiming to please but has some unresolved issues and doesn’t currently like contact and has jumping issues so is only going over cross rails. There is hope there as horse is better than when first started riding a month ago. Also, very friendly, walks up to me in the field, great on trails. If my options were limited I wouldn’t mind not making my Training level goals because horse is otherwise a fun horse and is a tryer.
Horse 3 - big, bold, beautiful. BIG, powerful gaits, naturally balanced, and flashy. Even though horse is big (biggest one on the list), easy to bring into the bridle. Not spooky but dropped me off what horse considered a small spook but feels like you are hitting the rafters when horse jumped. Plus side, horse was very apologetic and much more careful with gaits when I got back on and the next day. Could easily do what I want. Horse would definitely be on my list if I was looking for a horse.
Horse 4 - I swear has eyesight issues. Cute, nice size for me, balanced, not hard to get into the bridle. Likes contact, especially when worried and prefers a more confident ride. I prefer no contact and a horse more willing to take charge but not insurmountable issue. Good on trails, bit older for green but very sound. Would be on the list if looking for a horse.
Horse 5 - Gangly teen with ADHD, just all over the place, a bit looky but not really spooky. Young and unbalanced but cute and friendly. Would consider.
My first choice would be Horse 3 - really just checks all the boxes for me - personality, ability, soundness. Horse 4 and 5 would be next on the list, nice personalities, should be able to do what I want. Horse 5 edges out 4 due to being less anxious about leaving friends and less sassy if not ridden in a while. Horse 2 I wouldn’t mind having. If horse 3, 4, and 5 were not available and I settled for 2 and turned out 2 couldn’t overcome issues, I would still have fun riding that horse around. Horse 1 I may be tempted to buy if I had a really limited pool but if I were honest with myself, I would never like that horse. if horse 2, 3, 4, or 5 ended up as athletic duds or had career ending injuries, I wouldn’t mind seeing them in a field every day. Horse 1, meh.
So, ask yourself - what do you really like about this horse? Would you be content if it ended up topping out at beginner novice or as a pasture ornament? How much are you settling because the pool seems limited?