How to offer E-Invitations with different pricing options?

Hi!

Here is my in-progress shop - https://ink-pearl.myshopify.com/

I am selling physical invitations with variants for Size, Quantity and material, and I use a 3rd party app for variant text boxes to collect personalisation details.

I have now decided that I wish to offer E-Invitations. Naturally, this does not need an option for size or material or quantity, but it would have its own price.

Does anyone have any idea how I could offer this? I’ve used up my 3 variant options, so I’m kind of stumped.

Any help is much appreciated.

Thanks