The overhead mounts were about $125 each, compared to $75 to $100 for bike shoes. Yeah, they were more but I felt like it was worth the difference to free up the floor space and stop blowing seals. I think he will probably discount for two or more, I think I got about $10 off of that pice for 2. Best I can tell, the seal problem was caused by flexing the fork when the front wheel was held static, while the weight of the bike caused lateral pressure. I'm not an engineer but after I put tie down bolts on the shoes and started using tie downs vs the shoe fold over, I didn't blow a single seal. I replaced about 6 sets on 3 bikes in a 6 month period prior, so thats all I have to rely on.
Based on the installation, the holders are held in place with pressure in drilled holes, so I don't think that miles/vibration will have any impact, but I will report that back, good idea.