You can chose to have the Make an Offer button visible only for certain products through SKUs, collections, or tags (Also refer to Tutorial Video)

First you would have to identify the SKU, collection, or tag attributed to the product you wish to have the Make an Offer button enabled for. 

You would then go to the Make an Offer admin section, into Setup and click on the Incentive Configuration tab.

You will then scroll down to "B. Select the products you would like to enable the above incentives on:" where you will be able to access a drop down menu. 

You would then select "Show only on product skus, collections or tags selected below". Once this option is selected, you would insert the skus, collections, or tags into the correct field that are provided.

Please ensure that SKUs, collections, and tags are separated by a comma. You can then scroll down to the bottom of the page to save the settings and have the Make an Offer button enabled for those specific SKUs.