how much are those walmart kits?
considering you can get a 10g tank for about 5$ new, and sometimes free (at least at my lfs) then an appropriate filter would be about 10-15$ used, a heater for about 5-10$ and your all set.
Total: 25$
or, you could get a 55g for about 50$ used, a heater for 15$ and a filter for about 30$
total: 95$
bigger IS better
considering you can get a 10g tank for about 5$ new, and sometimes free (at least at my lfs) then an appropriate filter would be about 10-15$ used, a heater for about 5-10$ and your all set.
Total: 25$
or, you could get a 55g for about 50$ used, a heater for 15$ and a filter for about 30$
total: 95$
bigger IS better