OP I understand your situation I promise you. You will get no lectures from me. 20 is a lot to deal with by yourself along with having to deal with family obligations. Your hay bill alone has got be quite a burden.
Are these Thoroughbred mares that have been bred for TB racing? If so this is my area of expertise. Without looking at their pedigrees I can state for fact there is a very thin market for mares at just about any price. There is little to no interest for mares with little to no REAL pedigree. I am not just talking about well known bloodline names. There has to be some decent female, (distaff side) producing family up close to the mares for them to have reasonably broad interest. Who they have been bred to and who they are in foal to plays a big part to. Their age is another major factor Where you are located is a big part.
I have been a Bloodstock agent, Adviser for over 30++ years. Bred and foaled 20-30++ a year for myself and clients. Mainly for the KY and Mid-Atlantic market. Raced a few from time to time. I can look at a mare’s pedigree page, not just they bloodlines. Their complete pedigree, and produce record and tell you within minutes if they have enough value to look closer at things.
The above relates to the TB breeding side of things. When I was downsizing and selling our big farm. I approached some and listed the same for sport horse breeders. Got little to no interest. And some of the mares had some nice horses that we bred and re-schooled for sport horse use. And they were successful. The mares and their foals had the look and temperament sport horse people like. Unfortunately I received little to no interest. Just a lot of the standard tire kickers.
Not sure why you want to lease them. If they have good pedigrees, pedigrees that the average TB that knows what they are doing would find attractive. You might find some interest at a price and or free. Either way without some decent pedigree and relatively young I think you will find it difficult to give away. If your state has a State Bred breeders’ program this might help a lot. If there are some decent size farms that stand stallions they might have interest. But I wouldn’t expect them much money if any. Be happy that they will take them and wish for the best.
I have thrown saddles on mares that haven’t had a saddle on them for years. Always pleasantry surprised how quickly they fell back into the drill. In the end it didn’t make it much easier to find new homes for them.
Some of us, a lot of us who have horses in numbers on the farm. Will most likely at some point come to the cross road of a very tough decision. Euthanasia maybe the only thing in the best interest for all.
Sorry if I am being a Debbie Downer but this is the reality of the breeding business regardless of breed. The business and or ownership of horses in general. People that let their heart lead them. Can end up on the road to financial ruin. Relationship, person stress and break up.