prices of shrimps are pretty constant except for certain shops... u can get them at almost any lfs ... if u are afraid of them dying, u might want to try boxter shrimp.. u can get them under 5 bucks depending on size. they are pretty hardy too. or i can juz scout the beaches during low tides.. flips some rocks and u can fine piston shrimps.. but they can be quite irritating a nights. they produce a cracknig sound...
for the filter, if u do frequent water changes u can get a canister under 50 bucks. the freshwater fish distributor near T95 have some models.. but i would reco u get a more powerful one range from 60 - 75 (off course there are more expensive on if u have the cash to spare ) . filtration is something i think u should not save on