If you want something use something that mines more than a barge and can be used by alphas, then looking to to fitting out a mining battleship. It’s got that old school charm, and if you love mining that much, you’ll love all the micromanagement that is necessary to use it efficiently. You’ll also be the king of the asteroid belt, rocking 8 mining lasers as compared the the paltry two of the other ships.
More seriously though, as mkint said above, mining doesn’t get any better, at least not of the solo highsec variety. The game experience is exactly the same if you are using a Venture or a Retriever or a Hulk. If it is your life long passion to fly a barge or exhumer, and you absolutely cannot afford an ongoing subscription, I suggest you look into skill farming as a way to do so. Train your free alpha SP to cover most of the skills you need, and then finish off with a month of Omega, unlocking barges. Then sell off your SP each month to pay for your omega status.