Need a 30L tank / Also have a scratched-up 30L for a sump or something for someone

I feel like such a dummy! I have a 10 gallon tank and I was ready to upgrade to a 30L. And so my birthday came around and I found a deal on craigslist for a complete setup, beautiful black cabinet stand, tank, 2 water heater and a brand new Fluval 205 filter (only 4 months old). It also came with a normal hood light, but i knew I wanted to completely replace it.

I went to take a look at it and there was some calcium built up around the top and the lady told me she tried to clean it off as best as she could. No big deal, with some vinegar and elbow grease, I could get it off. Other than that, it looked fine.

It had a wire mesh top and they laid the light on top of it. I asked what they kept in the tank, and they told me a baby alligator---Whoa! I should have thought right there and turned down the deal. But I didn't think about alligators having finger nails/claws.

I got it home and was getting the build-up off just fine with some vinegar. I brought out a stronger light to see a little better and then all of these scratches became really visible! Then it occurred to me about the alligator.

I noticed a ton of tiny scratches going horizontally around the top and I could only guess she cleaned it with something abrasive. Her husband worked the fish department at Petsmart and is a serious reptile breeders. So I just assumed they knew what they were doing, at least 50% to take care of aquarium glass.

I thought it wouldn't be visible when I filled it up. I let the aquarium set over night and filter through. This morning, i turned on the light, the aquarium held the water, but the scratches were very noticeable to me.

What a bummer of a birthday present!!!! So now I'm on a hunt for a cheap 30L tank WITH OUT ANY SCRATCHES. Do you know of a place that might have one at a good price? I was trying to stay away from expensive aquarium stores, but Petco or Petsmart doesn't seem to have on their website.

Once I replace it, I'll have this one for someone that might would want it for a sump, breeder or hospital tank. It's not a showcase tank, for sure.

I'm also considering trying to buff some of it out and use it. I read online about using Cerium Noxide, but I don't know how much it costs, where it get it or if it's too much work to bother.