Hi,
The feature does not exists for the moment in HikaMarket.
In HikaShop, if you put a product with no stock, it can't be bought. You can set no price too (or set prices with ACL in order to hide them).
And you can activate the "contact button" per product.
So it is something which could be done with a little bit of customization, in HikaShop.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.