i don't think the OP has access to a home depot, but i agree that a do it yourself filter similar to Bunsen Honeydew's idea would be the way to go, especially with the limited budget.
as shown, most of the money will have to go to the pump. you want to be sure to get a reliable one, with more than enough pumping capacity. i am not sure what is available where the OP lives, but i don't think that a 1,000 gallon per hour unit, as Bunsen suggested, would be too large.
earlier posts in the Freshwater DIY section here have several designs for very effective filters.