Allow "Allow other amounts" to be used with Contribution Price Sets OR Allow Custom Amounts as a Price Set Field

When using a Price Set with a Contribution Page, it is impossible to allow the user to specify an another/additional amount.

I propose that either the option to "Allow other amounts" is allowed when using a price set (which I suppose in this instance should really be "Allow additional amount." OR that a custom price field is created that allows for custom amounts to be entered. I would prefer that latter, however I feel that the former would be far less involved.