IME, you ride in the saddle as is for a heck of a long time before you need to repair it.**
After that, you need to send it to a good saddler and have the seat replaced. IIRC, Bevals will do it for about $800. And they will do a nice job.
ETA: You can ride in that sucker until the leather on the seat offends your eyes or rolls up a bit and offends your booty. Until then, you can do what you want. When I was a kid, I warmed up horses in a pro's saddle that had a seat of duct tape.
Not a cheap repair in that location. They have to virtually take the saddle apart. You can have it patched for very little $50-100ish but it's not as nice looking as a repair. At least 4-5 years ago I was quoted $600 for the repair.
yup that's one of the most expensive repairs, not necessarily a full seat replacement since the tree seems sound and doesn't need to be changed. But changing only the leather on a seat is complicated, so depending on the repair person they might want to replace the whole seat and tree.
Also what is the brand? Remember to try and have the repair done by the original manufacturer so you get the same quality of leather and the saddle will retain its value. They shouldn't charge you more than an independent repair person.
I'm looking at a used saddle that has a spot where part of the seat has pulled loose from the piping that attaches the seat to the flaps, behind the twist. Tear is about 2 inches long.
Any ideas on cost to repair or how soon it would need to be repaired before it got worse?
YMMV - my experience, saddle was completely unusable within a couple months
If you're not prepared to patch (not always possible or recommended) or repair - especially if saddle is not priced to reflect the damage - then keep looking
Sometimes independents will give a lower quote than a brand shop but chances of leather matching (colour & quality) are reduced: of course, the local shop won't have the same shipping fees & may be more time efficient ... or not