Purchase question about lost mines

I already own the boxed set, is there a way that I can verify and thus get the roll 20 version or would I have to re buy?

You need to rebuy. While you get all the content that is in the physical editions of the 5e modules, you also get all the Roll20 setup done for you. This makes them pretty different products and not really exchangeable.

OK I've been told I could just do the work myself, being brand new to roll20, how hard would you say this task would be?

Scratch that I'm working off a tablet so I can't lay without monthly fees yet, I'd better get my laptop fixed

Well, I'm running Paizo's Iron Gods AP right now and I've done all the Roll20 work myself. I'd say I spend at least 8 hours on just roll20 prep each session + normal tabletop prep stuff. This prep time goes through the roof whenever I need to add a bunch of new NPC's/mobs and prep all their abilities to be easily accessible, especially if those abilities are not just "attack with sword".

Oh wow OK ty