Average Monthly Revenue per subscriber per month, the numbers

People say the completely random $1 per subscriber per month is our target, but if I send 1 promo per week (IM niche), to a list that has simply opted in for my freebie, assuming a good open rate of 20%, and 20% CTR, and I promote a $50 product for 50% commission that converts at a decent 3%, on a 10,000 subscriber list:

10,000 x 0.2 x 0.2 x 0.03 x $25 x 4 weeks = 1200 per month

Revenue per subscriber = $0.12 which is a small fraction of what I should be getting, but the estimates I'm using e.g. open rates, CTR, conversion rate, are all decent. Are my estimates accurate? What can I do to increase revenue to get up to the $1 mark? What is even an acceptable revenue per subscriber for a regular guy like me? Of course I would settle for $0.50 to be honest! I'm actually aiming for $0.30, realistically. But if I can't get something like $0.50 then expansion of list via paid traffic would not be viable, even with a good front-end offer with the goal of paying for some of my advertising costs, because solo ads for example average around $1 CPL so it would take a few months to see any profit from that subscriber, and cold traffic like banner ads have a lot lower opt-in rates than solo ad traffic. So I'm just trying to see how this business model is even viable. I know I need to squeeze as much per subscriber as I can, but I can't send promos every day at risk of burning my list.

I've also heard stuff from reputable people on this forum like GeraldGigerl saying that a list of 100 proven buyers is worth more than a list of 10,000 people who opted in for your freebie, which means 100x. He mentions that a buyer is worth $5-$10 per month so by his calculations someone who just opted in for your freebie but hasn't bought anything yet, might be worth on average just $0.05 to $0.10 per month down the line. I don't quite understand because if the figures were this low, then email marketing would not be viable and nobody would be doing it (which is obviously not the case).

People say promote high ticket stuff, but conversions will lower and is it wise to promote high ticket items to a mostly freebie seekers list that hasn't yet even bought a $7 product from me let alone $500. Just feeling a bit discouraged at the moment :-O I know they're only estimates but I can't help but feel the $1 is surely unrealistic (at least for someone like me). However I have no idea what I should realistically aim for as a good standard. I know there are so many variables but just a ballpark figure/rough average would be nice.

Cheers,

J