Most of us who run WooCommerce stores allow our customers to make their purchase online without having to directly contact us. For certain expensive or unique products, it makes sense to make them non-purchasable. The Non-Purchasable WooCommerce Products has you covered. You will be able to ask your visitors to contact you to complete their purchase.
The plugin is compatible with all product types, including variable items. You can change add to cart button and message on product pages from the back-end. It is also possible to hide the message completely.
This plugin is available as a free download. More info is available here.