I should tell you to walk away.
But my 2 experiences with buying sight unseen a horse that gives you a good feeling have gone extremely well. One was my OTTB who I fell in love with from a cute picture and a video where he was swarmed with flies. He was even more darling in person. No regrets.
My second experience was actually selling one to a woman who, same as you, saw his video on BigEq and fell in love with him. He was 10x more expensive than the TB, so a bit more of a gamble for her. What she ended up doing was paying to lease him for 3 months and had the option to buy at the end. He went out to Indiana and about a month later they called and said they didn’t need to wait 3 months, they wanted him. They loved him so much they ended up buying property and building a farm so they could take him home. That was about 7 years ago and as far as I know, they are all living happily ever after.
If you feel very strongly about this horse, do a thorough PPE and do it. As long as it is sane and sound, you should be able to sell it.
PS- the only horses I have really struggled with and ended up selling I knew the sellers and was able to try well in advance. He didn’t do well in the program I had available at that time.