Walmart offers the Marina Betta Aquarium Starter Kit in Sun Swirl, model no. 13350, for $6.06. Opt for in-store pickup to dodge the $4.97 shipping fee. (Amazon charges with same with orders of $25 or more with free shipping for Prime members.) That's the lowest price we could find by $3. It features a 0.5-gallon capacity and includes Nutrafin Max Betta Food and Nutrafin Betta Plus Conditioner.