"索价过高" can be translated into English as "asking price is too high" or "charging an exorbitant/excessive price".
"Asking price is too high" directly conveys that the price being requested by the seller is beyond what is considered reasonable or acceptable.
"Charging an exorbitant/excessive price" emphasizes that the price being charged is unreasonably high, with "exorbitant" and "excessive" both conveying the idea of going beyond what is normal or expected.