Fluval Spec Link
Smaller than you want and not a bow front, but it comes in under budget and will be able to grow low light plants. You can also replace the light easily. It is glass and very pretty. A good desktop size and will work well for a betta.
Fluval Ebi (or Fluval Flora) Link
This tank is a great size IMO. at 8 gallons you have room to design a nice aquascape and you can have some tankmates. The light it comes with should grow low to med light plants and you can easily add another to grow high light plants (although you will probably need co2. It is also a real "kit" as it comes with Fluval stratum, a great plant substrate. The link I added lists a higher price than most. I found my Ebi for $85, but alas, it is out of your price range. It is also a very nice looking tank with rounded front corners, so even though it isn't a bow it isn't exactly a regular old nano cube.
This tank in in your price range although smaller than you want. It is also a beautiful tank and the light should grow plants. I *think* it is a bowfront, or at least bow like, but I've never seen the tank in person so I don't know for sure.
Expensive and not a bowfront. But it is glass and fits your size requirements.
I would personally recommend not going with anything acrylic even if it fits your price range better because of the acrylic scratching so easily. It can make a beautiful aquarium look terrible really fast.